The Kongolese and they would make a good African themed DLC.
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Disclaimer again:
I am not an expert on the history of the region. There may well be inaccuracies and imbalances in all this. Some small of them may be intentional for fun. Please take easy for fun. 
Feature:
- This civ represents the kingdoms and empires in the Zimbabwe region.
- The Livestock Markets and the Huts are replaced with the Kraals.
- The Kraals uses Sanga Cattle as default livestock.
- Starts the game with Sanga Cattle and a Kraal builder.
- Has no the Mass Levies card, but from Age II the levied units can left with 25% HP instead of only 1 HP.
Potential AI leader
- Emperor Mutota of Mutapa
- Emperor Mutope of Mutapa
- Mambo Changamire Dombo of Rozvi
- Mambo Changamire Tohwechipi āChibhamu-bhamuā of Rozvi
Kraal
- Costs 300 wood, with a build limit of 8.
- With all functions of the Livestock Market and the Hut, and provides 25 pop, allowing villagers and healers to garrison in.
- Not training Sanga, but slowly and automatically spawning Sanga free.
- The Kraal (or called musha in Shona), meaning cattle pen, community building, or estate, is a common homestead form for the native peoples in southern Africa.
- Healer unit, with a train limit of 20. Uses 1 pop.
- Generates 1 influence for every 3 HP it healing for friendly units.
- Equivalent to the Mountain Monastery and University, with a build limit of 1.
- No unit can be trained, but there are 4 types of ceremony, similar to the Community Plaza.
- Villagers and Nāanga can build it and be tasked on it, up to 15 units. (All the 15 can be Nāanga.)
- Has a holy aura. Within the holy aura, buildings cannot be there and natural resources cannot be gathered, but the efficiency of ceremonies will be improved based on the number and type of those natural resources.
- A place for communication with ancestors and gods. Usually located in nature, surrounded with the beautiful and mysterious environment, like peaks, forests, caves or pools.
Default Ceremonies of the Sacred Site
- Spawn Nāanga.
- Improve military unitsā attack.
- Generate XP.
- Generate influence.
Default Technologies of the Sacred Site
- The Drum of Lords (I): Next Age up time -50 seconds.
- Mwari Cult (I): Gives Sacred Site a weak basic effect even though no unit is tasked on; The holy aura of Sacred Site becomes broader.
- City Walls (III)
- Rain Making Ceremony (IV): The fifth ceremony which can increase the Villagersā gathering rate on Fields is available.
Unique Military Units
Nevanji
- Ranged infantry hero with a shield and throwing spears.
- Prince of royal blood who would be made head of the army of Mutapa.
Uta neMiseve Bowman
- Light infantry and foot Archer unit.
- Trainable at War Camps from age II. Costs food and wood, and uses 1 pop.
Pfumo Spear Thrower
- Heavy ranged infantry.
- Trainable at War Camps from age II. Costs food and wood, and uses 1 pop.
- Throws spears and uses a shield, and with a ranged resistance.
Mapakatwa Swordsman
- Hand shock infantry.
- Trainable at War Camps from age II. Costs food and coin, and uses 1 pop.
Gano Axeman
- Heavy hand infantry.
- Trainable at War Camps from age II. Costs food and coin, and uses 1 pop.
- With a melee resistance and fast speed, pretty good at fighting against infantry and cavalry as long as able to get closer.
Tsvimbo Cudgeler
- Heavy hand infantry.
- Trainable at War Camps from age II. Costs food and coin, and uses 2 pop.
- Similar to the Maceman, pretty good at siege and fighting against siege units.
Rozvi Rifleman
- Skirmisher unit.
- Trainable at War Camps from age II. Costs food and coin, and uses 2 pop.
- Expensive but worthy.
- Ranged shock infantry.
- Trainable at Palaces from age II. Costs influence, and uses 1 pop.
- Similar to the Eagle Runner Knight.
Where their names come from:
Other military units:
Kurozva Spearman
- Outlaw heavy hand infantry.
- Trainable at Watch Towers from age II by default.
- Renamed from the current African Vagabond, just the same unit as the Jaga Spearman.
- Kurozva means āto plunderā in Shona.
Kurozva Archer
- Outlaw light infantry and foot archer unit.
- Trainable at Watch Towers from age II by default.
- Just the same unit as the Jaga Archer.
Boer Freebooter
- Outlaw light ranged cavalry / heavy ranged infantry.
- Trainable at Watch Towers from age II by default.
- Just renamed from the current Highwayman.
- Since the Great Trek, the Boer people had approached the Zimbabwe region.
- Outlaw light ranged infantry.
- Trainable at Watch Towers from age IV by default.
- Renamed from the current Colonial Looter, but with powerful stats and an English dialogue instead.
- The force of Cecil Rhodes, an ardent believer in British imperialism.
- Light ranged cavalry / light ranged infantry of the South Africa (revolution).
- Can switch between the mounted mode and the dismounted mode, like the mercenary Mounted Infantry.
- Trainable at Stables and Forts, and uses 2 pop.
- There will be some new cards to improve it for the South Africa. For example,
Boer Ponies: gives Boer Commandos and Hussars +10% speed.
Transvaal Civil War: gives Boer Commandos +50% HP and attack (which is equivalent to upgrade it to imperial level) at a cost of 2500 food. - The commando system is a traditional and representative tactic and organization in South African history. Originated from the Dutch Cape Colony, some native peoples such as Fengu and Khoi who learned to use firearms and horses were also famous for being good at it.
- Native unit of the Nguni minor civ.
- Uses an iconic assegai spear and a shield, with a train limit of 12.
- Can switch between the 2 modes.
Flank mode: Hand shock infantry lancer, having a ability to throw the assegai.
Central mode: Heavy ranged infantry, having a ability to stun enemy by shield-knocking in melee combat. - Those abilities are automatically activated when attacking with a cooldown.
- The iconic military unit of the Nguni, famous by the Zulu Kingdom.
Shakaās reforms have made his Zulu impis extremely good. Many Nguni tribes who had lost to Zulu, such as Mzilikaziās Matabele and Zwangendabaās Ngoni, used Zulu warfare techniques to conquer other peoples, resulting in a period so-called āMfecaneā.
Ngqika Warrior
- Native light ranged infantry of the Nguni (Xhosa) minor civ.
- Uses firearm, with a train limit of 16.
- Since the Seventh Xhosa War, the Xhosa under the leadership of Chief Sandile have begun to use firearms instead of traditional tactics.
Fengu Commando
- Native light ranged cavalry / light ranged infantry of the Nguni (Xhosa) minor civ.
- Uses firearm, with a train limit of 8.
- Good at fight against native units and mercenaries.
- The Fengu people were originally a part of the Xhosa. Because they couldnāt stand the harsh treatment of the Xhosa, they became a strong and valuable ally of the Cape Colony, such like the Capeās Fengu commandos led by Veldtman Bikitsha, until the governor of the Colony decided to renege on the promise.
Bakwena Rifleman
- Native light ranged infantry of the Tswana minor civ.
- With a train limit of 16.
- The Bakwena are a large Tswana clan in Southern Africa, and the predecessors of the major groups in modern Botswana and Lesotho.
Batawana Rifle Rider
- Native light ranged cavalry of the Tswana minor civ.
- With a train limit of 8.
- Cavalry from the northern Tswana clan, Batawana, armed with breech-loading rifles, met the invading Matabele people at the Battle of Khutiyabasadi.
Basotho Ambusher
- Native heavy ranged cavalry / heavy ranged infantry of the Tswana (Basotho) minor civ.
- Can stealth when dismounted, with a train limit of 8.
- Armed with battleaxes and old flintlock guns.
- In the Battle of Berea, Basotho cavalry ambushed a British column.
San Forager
- Native villager unit of the Khoisan minor civ.
- Weak and cheap, with a train limit of 8.
- Especially good at gathering huntable animals and berry bushes.
- Both the male and female version there.
Khoi Ox Rider
- Native light ranged cavalry of the Khoisan minor civ.
- Weak and cheap, with a train limit of 14.
- Khoi cattle-mounted herdsmen throwing spears to against the Europeans.
- In 1510, at the Battle of Salt River, Francisco de Almeida and fifty of his men were killed and his party were defeated by ox-mounted !UriĒāaekua (āGoringhaiquaā in Dutch approximate spelling), which was one of the so-called Khoi clans of the area.
Khoi Commando
- Native light ranged cavalry / light ranged infantry of the Khoisan minor civ.
- Uses firearms, with a train limit of 8.
- Mounting and dismounting is fast.
- Another valuable ally for the Colony. Andries Botha led his Khoi commandos to make great contributions to the Colony. He himself was greatly respected by his British comrades-in-arms.
Griqua Commando
- Mercenary light ranged cavalry / light ranged infantry.
- The most powerful commando type unit, and uses 3 pop.
Makololo Invader
- Outlaw heavy ranged infantry.
- Uses throwing spears and a shield, and only uses 2 pop.
- Moves fast, and good at siege.
Alliance
Unlike the Kongolese, they were quite unfriendly to the Jesuits, and not actively converted to Christianity, so I do not malke the Jesuits as an option.
Portuguese
- Something different. Provides a Prazo wagon instead of an Arsonel wagon.
- Prazo: The renamed Hacienda, able to spawn Chikunda, the renamed consulate Sepoy, instead of spawning Villagers.
- The spawn limit of Chikunda is initially 6 in the Age II, and gets +4 when hitting a new age.
- The Church Organs ships 1 Organ Gun for every 3 existing Chikunda for this civ.
Shona
- Zimbabwean Housestead Builders are available at TCs.
- Zimbabwean Housestead Builder: Can build Kraals, TPs, Ports, and Native Embassies.
- Legend of Great Zimbabwe: Gives a good trickle of influence; Zimbabwean Housestead Builders can build TCs and Palaces.
- Manyika Gold Mines: Ships 1 Gold Prospector Wagon; Villagers gather from mines 10% faster.
Khoisan
- San Foragers are available at TCs; Khoi Ox Riders are available at Palaces; Both are available at Native Embassies.
- The Mfecane big button is available at TCs from Age III.
- San Rock Art: Gives 50 XP for every minute, up to 30 minutes.
- San Diamphotoxin Arrows: Foot archer units and San Foragers have a weak but long-term poison damage.
Tswana
- Bakwena Riflemen are available at Palaces and Native Embassies.
- The Mfecane big button is available at TCs from Age III.
- Tswana Skin Cloaks: Villagers get +50% HP; other units +10% HP.
- Tswana Cattle Raiding: Receives a Sanga Cattle with every home city shipment; Converting herdable animals from opponent players can get XP bounties.
Matabele
- Impis are available at Palaces and Native Embassies.
- The Mfecane big button is available at TCs from Age III.
- Nguni Stick-fighting: Infantry get +10% melee attack.
- Nguni Cattle Grazing: Sanga Cattle are available at the Nguni settlements, Native Embassies and the livestock buildings; Gives +10 train limit for cattle animals.
Arabs
- Almost the same.
- Indian Ocean Trade Routes: renamed from the Blue Nile Ties.
- Swahili Relations: renamed from the Yemeni Relations.
Boers
- Trek Wagons are available at TCs.
- Sheep can be chosen at Kraals.
- Boer Volunteers: Ships 1 Boer Commando for every 3 minutes, up to 30 minutes; Boer Commandos are available at Palaces.
- Boer Diamond Rush: Ships 1 Diamond Prospector Wagon.
British
- Just the same.
Cards
-
Bushcraft (I): Villager gathering wood faster by 10%; Trees last +100%.
-
Svikiro / Spirit mediums (I): Ships 1 Nāanga; Nāanga are 20% more effective on the Sacred Site.
-
Mhondoro spirits (I): The Nevanji gets +50% hit points and attack, and can train pet lions.
-
Zimbabwean stone architectures (I): TCs, Watch Towers, and Palaces get +50% HP; Walls get +200% HP after City Walls is researched.
-
Dare ReHondo / War council (II): Ships 3 Camp Builders; Removes the levied unitsā multiplier against villagers.
-
Nhoo / Shona Shield (II): Pfumo Spear Throwers and the Nevanji +15% HP.
-
Varwi / Warriors (II): Replaces the train buttons of the Levied Bowman and Levied Spearman with their spawn options at Kraals, so one of Sanga, Levied Bowman and Levied Spearman can be chosen to spawn there.
-
Rozvi guns (II): Palaces slowly spawn Levied Gunners instead of training them; Rozvi Riflemen are trainable from Age II.
-
Muromo bull horn formation (IV): Hand units get +25% HP; Ranged unit get +25% ranged attack.
-
Magic Oil (IV): Gives Nāanga +500% melee attack; Gives other military units +5% melee attack.
Maps
To fill the rest of Africa.
Congo Basin
- Almost the same, just replace the Yoruba with the Luba.
Lake Victoria
- Almost the same, just replace the Sufi with the Luba.
- Located south of the Congo Basin and Lake Victoria, west of the Swahili Coast. Roughly covers the modern Zambia and northern Zimbabwe.
- With rainforest similar to the Congo Basin and tree savanna similar to the Swahili Coast.
- 2 Luba and 1 Tswana settlements, or 1 Luba and 2 Nguni (subgroup: Ngoni) settlements.
- Has a Trade Route.
- Between the Congo Basin and the Zambezi Basin.
- The overall style is similar to the Congo Basin, but filled with a lot of copper mines.
- 4 Luba settlements.
- Has a Trade Route.
Angola
- Located southwest of the Congo Basin.
- There is the coast. The shore is a drier, fertile area with open spaces, while further inland is dense rainforest.
- 2 Jesuit holy sites and 1 Luba or Khoisan settlement.
- Has a Sea Trade Route.
- Located south of the Angola.
- A desert with a coast.
- Almost all the Treasure Guardians are Colonial Looters.
- 1 Khoisan settlements.
- No Trade Route.
- Located northeast of the Namib, west of the Zambezi Basin. Roughly covers the modern northwestern Botswana.
- There are rivers and oases with many animals in the desert. You can fish but have no water drop-off point for home city shipments.
- 2 Tswana and 2 Khoisan settlements.
- No Trade Route.
- Located east of the Namib, south of the Okavango Delta. Roughly covers the most of the territory of modern Botswana.
- Dry inland desert with a few natural salt mines.
- 4 Tswana settlements, or 3 Tswana and 1 Khoisan settlements.
- No Trade Route.
- Located east of the Kalahari, south of the Zambezi Basin. Roughly on the border between modern Botswana, Zimbabwe, and South Africa.
- As the name, a veld area full of bushes, with many trees and berries.
- 2 Tswana and 1 Nguni (subgroup: Matabele) settlements.
- Has a Trade Route.
- Located east of the Bushveld, south of the Zambezi Basin. Roughly covers the modern southern Zimbabwe and southern Mozambique.
- Similar to Bushveld but clearly less trees. A few capturable wild Sanga Cattle and gold mines there.
- 2 Nguni (subgroup: Matabele), and 2 Tswana (subgroup: Basotho) settlements.
- Has a Trade Route.
Highveld
- Located south of the Bushveld and Lowveld. Roughly the area of Gauteng in modern South Africa, where the Boer states were established.
- Even less trees than the Lowveld, but more capturable wild Sanga Cattle.
- 2 Tswana (subgroup: Basotho) and 2 Nguni (subgroup: Xhosa) settlements.
- Has 2 Trade Routes.
- Located west of the Bushveld and highveld, south of the Namib. Roughly the modern Northern Cape of South Africa.
- Even Dryer than Highveld, and also capturable wild Sanga Cattle there.
- Many Treasures are Livestocks.
- 3 Khoisan settlements.
- Has a Trade Route.
Natal
- Located southeast of the Highveld, separated by Great Escarpment. Roughly the modern KwaZulu-Natal of South Africa.
- There is the coast and hills.
- 4 Nguni (subgroup: Zulu) settlements.
- Has a Sea Trade Route.
Cape of Good Hope
- Located south of the Great Karoo, separated by Great Escarpment. Roughly the modern Western and Eastern Cape of South Africa.
- Many Trade Posts, and they provide a higher number of resources.
- 2 Nguni (subgroup: Xhosa) settlements, or 2 Khoisan settlements.
- Has a Land Trade Route and a Sea Trade Route.
Madagascar
- A big island which has a high mountain in the center and surround by sea.
- 3 Jesuits holy sites. In there, they will speak French instead of Spanish.
- Has a Sea Trade Route.
Minor civs
Subgroup
- Unique feature of the minor civs of Nguni and Tswana.
- Nguni has 2 type: Zulu / Matabele / Ngoni (just the name is different), and Xhosa.
- Tswana has 2 type: Tswana, and Basotho.
- On a map, the same minor civ will only have one type of subgroup.
- I think this mechanic is interesting, and itās pretty effective at representing the scatter due to Mfecane without introducing lots of minor civ.
- The unique big button for the Zimbabweans, and for the minor civs of Nguni, Tswana and Khoisan.
- Researchable from Age III.
- Once it gets researched at any buildings by anyone first, all the other Mfecane in this game will automatically become researched too. This symbolizes that the game has entered this period, and everyone is a part of this period.
- Different effects will be provided for different subgroups.
Nguni
- Impis are availble by default.
- Nguni Nkosi (II): Ships the Nguni Warchief, a foot ranged African hero unit armed with assegais and a shield.
- Nguni Stick-fighting (II)
- Nguni Cattle Grazing (II)
- Nguni Cattlehide Shields (II): Impis get +10% HP and +10% resistance.
Nguni after Mfecane
- The Nguni settlements and the Nguni Warchief are renamed under the name of the subgroup in the map. For example, they will be renamed Zulu settlements and Zulu Warchief in the Natal.
- Zulu, Matabele and Ngoni: Impis attack 10% faster in melee, get +10% speed and +50% train limit; they and the Warchief now look like using Iklwa spears in melee.
- Xhosa: turns Impis into Ngqika Warriors; Ngqika Warriors and Fengu Commandos are available, and Impis are unavailabe now; The Xhosa Warchief also changes to use firearms.
Tswana
- Bakwena Riflemen are available by default.
- Tswana Kgosi (II): Ships the Tswana Warchief, a mounted ranged African hero unit armed with firearms.
- Tswana Skin Cloaks (II)
- Tswana Cattle Raiding (II)
- Tswana Totemic Animals (II): Receives a group of animals, including a pet warthog, a pet lion, a pet crocodile, a pet monkey, a pet elephant and a Sanga Cattle; The Tswana Warchief and settlements can ālevyā this group multiple times with a cooldown; Pets get +20% HP and attack.
Tswana after Mfecane
- Ships 1 Makololo Invader for every 2 minutes, up to 30 minutes; Makololo Invaders are available at the outlaw buildings.
- The Tswana settlements and the Tswana Warchief are renamed Basotho in the Lowveld and the Highveld.
- Basotho: Basotho Ambushers are available.
- Tswana: Batawana Rifle Rider are available.
Khoisan
- San Foragers and Khoi Ox Riders are available by default.
- San Rock Art (I)
- San Diamphotoxin Arrows (II)
- San Trance Dance (II): Can get XP bounty by killing huntable animals by San Foragers; healers can heal units faster.
- Khoi Nomadic Culture (II): Sanga Cattle and Goat can be trained by Khoi Ox Riders, and can be tasked at Khoi Ox Riders for fattening (5 animals to 1 Rider); Khoi Ox Riders can gather food from herdable animals, and automatically gather herdable animals if they are fattened and tasked on the Riders.
Khoisan after Mfecane
- Ships 1 Griqua Commando for every 6 minutes, up to 30 minutes; Griqua Commando are available at the mercenary buildings.
- Khoi Commandos are available.
Luba
- Luba Bowmen and Luba Swordsmen are available.
- Luba Mining Monopoly (I): Ships 1 Copper Prospector Wagon for every 5 minutes, up to 1 hour.
- Luba Dried Fish Trade (I): Ships 1 Fishing Canoe; Fish last +100%.
- Luba Government Form (II): Economy techs cost -20% cheaper and get researched instantly.
- Luba Sacred Lineage (III): Ships the Luba Balopwe, a foot hand African hero unit armed with an iron adze; Luba units +10% HP and attack.
- Luba Ivory Trade (IV): Ships 8 huntable elephants; Villagers can generate many coin and influence when gathering food from huntable animals.
[Edited for Note] How Subgroups and Age Up Allies work together for this civ:
The different types of subgroup technically wonāt count their units in the same train limit slots. So, if the Zimbabweans are allied with Matabele, and have a TP at the Nguni settlement whichās subgroup is Xhosa (different from Matabele), thenā¦
Before Mfecane ā After Mfecane
Palaces: 12 Impis from the Matabele ally ā 18 Impis from the Matabele ally.
Settlement TP: 12 Impis from Nguni ā 16 Ngqika Warriors and 8 Fengu Commandos from Xhosa.
Native Embassies: TWO Impi train buttons with 12 limit respectively ā just the 3 train buttons for those 3 units.
If allied with Matabele and have a TP of Zulu, Matabele or Ngoni, that is simple, they are the same subgroup. You will have 24 (36 after Mfecane) Impis at Palaces, the TP, and Native Embassies.
It can be deduced by analogy that how it they works if allied with Tswana and has a Basotho TP.
For other civilizations, there is no need to worry at all, because on a map, the same minor civ will only have one type of subgroup.
An important reference source:
