IMO from what I've seen of M2TW so far: The battle AI and pacing of battles is a nice improvement over the 2 minute battles and chain routing of RTW.

RTW was always plagued by a virtually worthless battle map AI. There was no such thing as a long, epic battle. It was simply a matter of lowering the enemy's moral (via 900 different ways...all very easy in fact) and then flanking them and watching the ensuing chain route. Either that or doing absolutely nothing and just waiting for the AI general to run a suicide charge into your 3500 strong army.

Grinding at an elevated position, using cover, reforming after "round 1" ...absolutely none of this came into play with RTW. It was simply line up , and win within minutes. Just a cut to the chase version of total war..and by far the worst battles in the series.