Ahhh mounting troops, something it should be doable too and I forgot to include in the pool.
I have longed for the possibility of the rider surviving the death of it's stead for a long time now. But CA can't do it for how the units works. Also I asked about mobs of warriors and peasants with different weapons (hammers, axes, spears and swords) all in one wobbly mess, can't do either because of the way units works.
If given further tough, a lot of the issues with the franchise (real time tactics side) as a whole stem from how the units are managed. Pathfinding, AI, artillery, hell even things like the automatic towers.... Since units are a block, and they can't be separated in anyway, it's cumbersome and monolithic. If we had more control over individual units or the engine were able to manage them, then things would be far better, specially in sieges and urban environments.
What I'm thinking about is somehow like the units are controlled on the Cossack series. For those of you that don't know there units can be formed when you have a bunch of soldiers, a officer and a musician you select them all and could create a unit not unlike the ones we are used on Total War, but if you preferred it (for any reason) you could still control individual soldiers in any fashion you wanted. While in Cossacks games this was almost never necessary, I could see how it could be used on games like Total War.
Picture your warriors group breaking up into smaller bands and breaking inside buildings in the middle of a siege (to pillage, take refuge or man up siege equipment or gates). Or that after a cavalry charge some riders lose their steeds but get on their feet and keep fighting on foot until the end of the battle (or they get/steal another horse). These things might not change the face of total war battles forever, but sure could help a lot to immersion and fun.