To preface, I am well aware that FE has no intentions of changing any of the AoK civs in a major way, due to a certain belief that they are iconic and shouldn’t be tinkered with. Now, despite that…
For what it’s worth, the new civs all get pretty much 2 UUs and a lot of unique mechanics around them.
The older civs do deserve some love in that aspect, regardless of whether everyone on the forum agrees with the idea that the old civs (designed in 1999, for worse hardware, with less finances) could get various changes to make them more “modern” when it comes to conceptualization and game diversity/balance/completeness.
The AoK civs are as follows: Britons, Byzantines, Celts, Chinese, Franks, Goths, Japanese, Mongols, Persians, Saracens, Teutons, Turks and Vikings.
I will briefly outline what additions in terms of UUs/UBs could potentially make sense for (some of) those civs, in my opinion. Feel free to share your own take.
Britons: not sure
Byzantines: for such a defensive civilization, an Unique Building could make a lot of sense, in particular one that heals nearby units. Maybe an unique building that is a monastery, but also heals nearby units in a 5-10 tile radius. They could benefit from other defensive oriented bonuses too, such as outposts having 5 garrison space, but that is out of the scope of the current post. Or one could explore the Byzantine military historically and derive some ideas from there.
Celts: they could use a light cavalry sort of unit, as currently outside of their siege, it does seem like they have no way to deal with ranged compositions at all. Maybe one with higher pierce armor, maybe a total replacement for the scout line for them (and for the Britons?) that has a scaling/higher pierce armor. Afaik they did have some sort of light horsemen history-wise, but as Spirit of the Law noted in his recent video, Celts in AoE2 are a bit of a mish mash and it’s hard to pinpoint the exact historical period and concept they are based on.
Chinese: it could either be an Unique Unit, or an Unique Building, if it was a unit I would place my bets on a heavy infantry sort of mix between spearman and militia line, think Flemish Militia crossed with Serjants. If it was a building, I’d go with something that trickles resources over time based on certain conditions (like your villager count, or military count). Alternatively, it could be an unique siege weapon- the current scorps with +4 damage and no Siege Engineers are bad. But a cheap early sort of gunpowder unit, 9-10 range, mix between mangonel and bombard cannon, I could see. AoE3 flying crows anyone?
Franks: considering how bad they are in trash wars, I do believe there is place for improvement in their post imp, that doesn’t focus on their cavalry, but I would have to dive deeper into what historically accurate options there are. I can see a highly mobile light artillery unit being useful to the civs, though don’t quite me on history.
Goths: not sure yet
Japanese: I did see something about Samurai getting their intended ranged attack, but they would need more than that. They have enough in terms of infrastructure, I do believe their military is lacking though. Some expensive cavalry unit with a “special” aura-like ability like the Daimyo could be an option, but then again, they would need a build limit, maybe 1 per castle that you currently have? That does seem like a plausible enough solution.
Mongols: their siege is good, their cavalry is good, but their infrastructure leaves much to be desired, which, all things considered, is fair, for a civ coming from the steppe. I do believe they could make use of an economic-oriented unique building though, maybe… that spawns deer over time? Or is that too ridiculous and impossible?
Persians: I do believe that they could (hear me out, I will be reasonable) have an AoE4-style cavalry archer that can shoot while moving. They currently lack any backline damage-dealing units, their CA are bad, simply because they lack Bracer, but aside of that have full upgrades, and are historically significant (Parthian Tactics was in fact the “art” of shooting while retreating on horseback, employed by the Sassanids). Considering they would have just 6 range in imperial, and need a mass, I think an unique replacement for the CA-HCA line that can shoot while moving could make a lot of sense. Alternatively, it could be some other CA unit with a special ability.
Saracens: Historical accuracy aside, Genitours replacing the whole skirmisher line for Spanish, Portuguese, Berbers and Saracens, could make a lot of sense. Genitour in Feudal, Jinete in Castle, Elite Jinete in Imperial, where the Elite Jinete has 5 range, plus the stats of Elite Genitours now.
And the civs getting certain buffs for them- Saracens getting FU + Zealotry benefitting them, Berbers getting a discount on them (turning the stable units discount into “mounted units” discount, Camel Archer price adjusted accordingly). I don’t think that Saracens need anything else, but their big weakness to archer civs should be noted, as despite having FU skirms, their eco isn’t at all good enough to compete. In addition, all of those civs have good HC, champs, and other anti-infantry units to handle halb spam with.
Teutons: What was the thing that a lot of people wanted again? Crusader knight? Like a weaker boyar made from the stable? A clear weakness Teutons currently have is their focus on close to mid range combat and lack of speed, maybe a unique siege unit, or a monk, could also be implemented, though I’d rather have something thematic that looks cool. The “weaker boyar” could have some special stats too, like taking less bonus damage from anti cavalry attacks. And still, Teutons are notoriously weak against archers, Boyars won’t help with that.
Turks: Unique Bombard cannons anyone? Dardanelles artillery? It’s not like they need much aside of that, though I could see an argument regarding their lack of options to deal with archers. I’d even consider giving them a lighter anti-archer unit in the castle age, something like the abus gun in aoe3. 7 range, deals a bit of splash damage with every shot, gunpowder unit similar to the janissary, but made from the siege workshop, with food and gold. 7 range in imp, but affected by the UT for +2.
Vikings: The whole civ feels like it lacks identity, for balance I’d give them better scorpions, but I’m not sure what exactly the civ needs in terms of completeness. I do believe they could use some infrastructure changes, such as having longhouses instead of houses, that support more population (and have extra functions? Heal the units around them? Allow villagers to be garrisoned? Provide some other utility?)