The insane Bob has pointed out a good concept. Character traits determining the style of attack or defense. That would be fantastic.
All those traits like "good cavalry commander" would make so much more sense.

BTW, I noticed that the "Eastern General"-unit is not so suicide happy.
You can even trust him with the command of a co-attack force. If you use Horse Archer-only armies he will happily skirmish but keep his own unit in the back. At least thats my experience on vh/vh with the Parthians.

R'as