Hm, a Total War game mainly is about war, and battles, that´s the strong point of the series. In MTW the battles were more important because you had to win the field battle in order to capture the province while in Rome, due to the map system of free army movement, you could maneuvre troops about in one-unit stacks if you wanted (something the AI does a lot). Perhaps armies should have a general (a.k.a family member in RTW) as prerequisite to move an army about, no more no-name captains. That would certainly lead to more concentrated armies and - potentially - more decisive battles.