So Aoe4 factions are supposed to be quite unique from one another based on the trailer, at least I hope so. That means you can get factions that play completely different from one another kind of like in Warhammer series. Since they are historical faction not all of them should play completely differently. However some major changes should be present among them.
Originally in Aoe2 factions were distributed based on different culture-region which was visible on their unique architecture type. However I think on Aoe4 that should be even more deeper.
Each faction should have two trait, one is based on the culture-region they are from, the second one their own unique traits. Factions under same culture-region will have similar architecture type, similar ethnic units that are different from other culture-region groups unlike Aoe2 where Aztecs had European crossbowmen, also their own tech tree that enables them various unique buildings and units.
For example European faction can have university while middle Eastern faction have madrasa. Meso-american faction can have cheap slightly weaker units. Steepe faction can have movable building like tents.
Dividing in such groups early on can allow future inclusion of faction much simple as they can part of certain group and carry those traits alongside their own unique traits and of course unique units.
As for the culture-region themselves I think there can be 14 different types. Now this are just wishful thinking, I don’t expect all such factions to be in the game even after all the dlc comes. However two third of them should be.
Western Europe: British, Franks, Celts, Scots
Gothic/Central Europe: German, Polish, Goths
Viking/Norther Europe: Vikings or maybe Swedes, Danes, Norwegians (I know originally they shared the same architecture type as central Europe however Viking faction should play completely different from other European faction).
Eastern Europe: Rus, Slav, Bulgaria, Lithuania.
Eastern Mediterranean: Spain, Portugal, Italy or maybe Venice, Milan, Genoa if they want to be more historically accurate.
Western Mediterranean: Greece, Byzantium, Georgia
Middle East+North Africa: Mamluks/Saracens, Berbers, Moors, Levantine.
Persian: Persia, Hashashins (just wishful thinking).
Steppe: Mongols, Cumans, Kazhar.
African: Ethiopia, Mali, Bantu, Somali.
South Asia: Rajput, Bengal, Tamil (India is too diverse so at least three such faction can represent them nicely)
East Asia: Tibbet, China, Korea, Vietnam, Japan. (Japan should have lots of completely different units however their playstyle should be similar to other East Asian faction)
Southeast Asia: Brumes, khemer, Malay, maybe Thai.
Meso-american: Aztecs, Mayan, Inca.
Also there can be some fusion faction. These can have culture-region traits half from one group and half from other; having access to different units from both groups.
Turks(middle East+Steppe), Tatars(middle East+Persia), Manchu(East Asia+steppe), Jerusalem (western Europe+middle East), Normans(Western Europe+Viking), Magyar (east Europe+steppe).
So what do you guys think? How do I like my ideas? Share yours. Also tell me how do you think each of this group should play that’ll make them completely stand out from one another.