Let’s say Relic randomly and out of nowhere says, “We will not be working on any more civilizations, but are open to suggestions for what you want to be added in future DLCs”, what would you suggest to them? (Other than a strongly worded letter about how we want civs… but that’s out of the question. Also, the game is balanced, you don’t need more patches or bug fixes).
I’d suggest making each civ completely unique from each other, no copy and paste MaA or archers and sprinkle on top with one or two unique units and upgrades.
Add more player expression items like flag banners hanging down from walls and towers and keeps.