I believe there are some things that ought to be brought back / over to the franchise.
- The ability to change diplomacy mid-game, forming and breaking temporary alliances
- The ability to trade with your allies (hopefully more than just gold, paying tribute shouldn’t be instant)
- Complex naval warfare (with boardings and crashings much in the style of the game Sparta, but hopefully with some cannons in the mix).
- Cavalry should do more than just move fast, cavalry charges should not stop abruptly when entering combat, it seems unrealistic. Infantry and archers should be knocked down (as they are in Battle for Middle Earth). Charging against pikemen should mean almost instant death.
- No more destroying fortifications with swords and arrows