The whole nature of battles should be changed to be more historically accurate. In RTW/M2TW we are used to seeing the AI attack with a few militia/peasants/veites or some such trash units. Rebels with a few muddy peasant units inside spawn on the map regularly and annoy the player without producing any challenge, just a loading screen and 2 minutes walking towards the AI that is hill camping.

Less frequent annoying little skirmishes and more decisive battles are needed. I think they managed to fix that for S2TW since the AI frequently attacks with stacks of elite samurai units, though the autocalc is broken in that game.