Rome 2 will be a nice change from Japan. I hated fighting in Japan on campaigns because it's such a narrow strip of land. Hopefully in future games they will add all of Asia instead of just Japan. I would love playing as India with their elephants, chakrams, serrated whips, etc and china with their repeating xbows.
Also, I had an idea for nomadic armies in campaigns. And since they havent sent me an activation key on TWC yet, I wanted to see how it would fair here. What if each general had attached to them a "camp" agent that had separate xp from the general, but with that xp u would be able to unlock units for recruitment. The general could recruit at any time but the gold would scale the further it is from the home region. If the general died, the army would have to move back to their home region to get a new general or merge in to an existing army in x amount of turns, or they would all disband.