Heroes with aura are nice, though I think if done right heroes with abilities (like in Warcraft for example) wouln't be so bad. Ideally the abilities should be realistic ,not the 1-hit-kill-several kind but a rally shout and battle horn ability based on real historical evidences would be nice. This way heroes would have a more noticeable impact on battle but only when his troop is around. This give me a thought, we can have army-orient heroes and solo-orient heroes. The former is generally weaker but have greater boost ability to his army and the later is more of a super-soldier, able to single-handedly kill dozen units (though not half the enemy army of course). And I think Rogers' suggestion about morale drop when a commanding hero is slain is nice, not sure how should we implement this. I don't think reduced hp or trying to flee would be good, the former unrealistic and the later seems meta-gamey to me, perhaps a slight penalty to attack stat? This penalty will be removed after a certain time (kinda like a debuff) to simulate the army regrouped.