These fantastic concepts illustrate how AoE4’s current ‘staleness’ has nothing to do with the number of civs (8). “Too few civs” doesn’t necessarily equate a stale game.
The popular (easy to play) civs are French and English, two awfully INSIPID, unimaginative and monotonous civs, with a profile, structure and gameplay all tediously mimicking AoE2. What a waste of franchise! The Mongols and Delhi are much better civs.
This (not bugs, not graphics, not civ number) is what threatens and is corroding AoE4: this boredom, this playing it too safe with civ/gameplay ideas. Bugs already fixed… but even AoE3 has more players than AoE4 now.
However the good news is, AoE4’s redemption and playerbase revival is very possible - with a DLC addressing the real problem - and hopefully coming soon.
Deeply imaginative, unique civs with SYSTEMICALLY transformative, revolutionary new mechanics, like the Turks in this Topic with @Kameho3743’s ‘Captive system’, ‘Viziers’ or @SuicydalMonk’s ‘Hybrid nomad-settled’, ‘Wolf taming’, ‘Army band songs’, or the Majapahit civ topic with Spices mechanic, that’s the only thing that can resuscitate AoE4 and turn it into what it could and should have been all along.
AoE4 doesn’t need 40 factions, the entire Balkans. It needs just the right civs, historically significant and unique, with fresh, systemically transformative, game-changing ideas. ‘English’ and ‘French’ are not this.