What I want to see is coordinated AI. I would like to see the units act as a group with a battleplan, not like a bunch of independent armies. The grand plan of the army should take into account the strengths and weaknesses of each unit, and not compromise the overall line by trying to shuffle the units around at the last minute. At the very least, pick a tactic and stick by it. When the AI changes it's mind this usually does more harm than good.