Thank you! Now for Eastern Europe:
Tatars (I think they would be best as a minor civ, rather than full civ, most of the Tatar Khanates were past their prime, and I don’t think their gameplay would be too different from Lakota
Location: Eastern Europe, Siberia, Mongolia, Himalayas
Language: Crimean Tatar
Unique Unit: Tatar Horseman (Horse archer with a bonus against villagers and buildings, like Lakota Bow Rider)
Techs:
Kazan Bazaar: You and your allies get one crate of a random resource for each TP your team owns
Tatar Raiding: Grants a siege bonus to all cavalry
Genghis Khan’s Children: Grants 1,000 XP
Refers to the fact that most of the Tatar Khans were descended from Genghis Khan
**
Kalmyks
Location: Eastern Europe, Mongolia
Language: Kalmyk Oirat/Mongolian
Unit: Kalmyk Rider (Hussar-type cavalry with a lance, maybe a charged melee attack?)
Oirat Migration: Increases TC build limit by 1 and grants you a TC wagon
Nomadism: Grants you 2 wagons to build a village (Chinese house)
Kumis: Mare’s milk liquor strengthens your Kalmyk cavalry, increases their attack by 10%
**
[Zaporizhians](Zaporozhian Sich - Wikipedia) (Subsection of the Cossacks)
Location: Eastern Europe
Language: Ukrainian or Russian
Unit: Cossack Renegade (clone of the Russian Cossack, so a weaker Hussar but big build limit), Hetman (hero-type unit which boosts Renegade stats)
Tech:
Cossack Diplomacy: Grants you a Hetman, and allows them to be trainable if you lose it.
Cossack Horses: Modestly increases HP and Attack of melee cavalry
Steppe Feuds: The perennial Cossack-Tatar rivalry grants your cavalry a moderate defense against ranged cavalry
**
Circassians
Location: Eastern Europe, Caucasus, Balkans, Egypt
Language: Circassian
Units: Circassian Cavalry (Melee cavalry with a charged bow attack), Mountain Raider (skirmisher-type unit)
Techs:
Prized Warriors: Grants 4 Mamelukes
Reference to how many Mamelukes were originally Circassians who were sold into slavery to become warriors
Circassian Beauty: Increases settler recruitment speed
Dogged Fighters: Boosts HP of Circassian Cavalry and Mountain Raiders
**
Armenians
Location: Middle-East, Anatolia, Balkans, Caucasus
Language: Armenian
Unit: Armenian Archer (standard bow unit), Monk (healer unit)
Techs:
Mountain Refuge: Grants you one Mountain Monastery wagon to build a Mountain Monastery on a mine, can train Armenian monks as long as you continue to own the TP on an Armenian site
Mountain Warriors: Boosts attack and HP of all melee and archer units
Land of Faith: Healers gain increased HP and healing speed
**
Greeks
Location: Balkans, Anatolia, Black Sea region
Language: Greek
Unit: Armatoloi (Hybrid Musk-Skirm)
Techs:
Philhellenism: The love of all things Ancient Greek speeds up research rates
Mediterranean Diet: Healthy food options lead to a modest discount on Settler recruitment cost
Greek Revolution: Majorly accelerates recruitment speed and increases recruitment limit for Armatoloi
**
Crimean Goths
Location: Eastern Europe, particularly Black Sea region
Language: Crimean Gothic
Unit: Balaklava Rifleman
Techs:
Crimean Fortresses: Increases HP and attack of forts, outposts, and walls
Crimean Vineyards: Increases Mill and Plantation gather rates
Ancient Ways: Hand infantry attack, HP, and recruitment speed are all modestly increased
**
Prussians (as a stand-in both for Prussia itself, as well as Baltic and Volga Germans)
Location: Northern Germany, Baltic, Central Russia (Volga Germans)
Language: Brandenburger German
Unit: Landwehr (slow but strong musketeer), Sword Brother (Recycle the model from campaign Boneguard)
Techs:
Teutonic Legacy: Increases number of Sword Brothers you can recruit, boosts melee attack for all melee infantry across the board
Clausewitz’s Principles: Increases recruitment limit for Landwehr, boosts shooting stats of all Musketeer-type units
Agricultural Expertise: Increases mill gather rates
**
Wallachians
Location: Balkans, Black Sea region
Language: Romanian/Aromanian
Unit: Vlach Boyar (Cuirassier equivalent)
On the right, with the sword and tall fur cap
Techs:
Legacy of Vlad Teppes: Melee units gain increased attack
Land Beyond the Forest: Grants a crate of wood for every 3 minutes of game time, up to 30 minutes
Danubian Sich: Grants a delivery of 8 Cossacks
**
Szeklers
Location: Eastern Europe, Balkans
Language: Hungarian
Unit: Szekler Hussar (boosted up Light Cavalry, akin to Magyar Hussar), Szekler Grenzer (Light infantry with a double-barreled musket that can be upgraded to have a charged double-shot attack)

Example of a double-barreled Grenzer rifle
Techs:
Carpathian Mining: Boosts coin output from mines, increases mine yield
Cziskos: Allows Szekler Hussars to gather from livestock, unlocks cattle from livestock pens
Border Defense: Grants your Grenzers a charged attack which allows them to fire twice in quick succession