Well, it would be nice for Heroes to have their own loyalty score, and perhaps their own initiative score.
Loyalty woud effect their chances to get Bribed by the enemy, defect, or Withdraw from combat without orders. The higher the loyalty score the less likely these things will happen. Usually these things would never happen under normal circumstances anyways, unless the Opponent tries to use Money to bribe them, or Domination/mind magic to make them defect, as well as Diplomacy to try and make them defect, or Fear magic or Diplomatic threads to make them WIthdraw from engagements.
non-commital withdrawal (as in, not ordered by the Channeler, and just a spur of the moment thing NOT planned for) should probably cause the loss of the turn, the army would retreat towards the nearest city at a pace slightly faster than it normally can go, and probably a 5-10% loss of units that are dissilusioned as well as a slight penalty for loyalty scores of all Champions in the army.
If a hero's loyalty drops to 0, then they can either fade back into one of your cities, perhaps to return after re-gaining a sense of patriotism (you are fighting a losing war against a nation of opposing alignment) or to even become an NPC freelancer, that may or may not be able to be hired as a Merc to either fight (again, but with more money) or complete Quests for you.
Initiative is how individualistic the Champion is. Each hero would have a (somewhat) randomly generated peronality towards each faction including your own, while your nation is the one greatest favored by that hero (usually-sometimes its because you are the only nation able to do something about fighting Nation X who the Champion hates).The hero's personality could also effect how Honorable they are. Whether they go through the motions, or are true Mercenary.
True Mercenaries are only paid in Gold, while your Champions are paid in both gold and prestige (less of each). If a hero has high initiative and high Honor, then he will want much more prestige than pay, and not that much pay. He will also never negotiate with an enemy, never accept a bribe, and never defect or even withdraw. Well, he might withdraw if he thinks the battle is unwinnable if he does not also have High loyalty.
If your hero is low in Loyalty and High in Initiative (and low in Honor) then he will more easily accept bribes or be pursuaded to defect through diplomatic means. Loyalty protects against both magical and mundane attempts at conversion, while Honor protects against mundane injury (bribe, diplomacy, threats). Someone with High initiative will have the effects of their character "Amplified". High Initiative, Low Honor, and Low Loyalty will switch many sides and often. High Initiative High Honor and low Loyalty will never switch sides unless its by magical means. High Loyalty, Low Honor, and High Initiative will accept a bribe if its good enough (to outway his loyalty) but will never be defected/routed through magical means. A Champion with low initiative will always fall somewhere in the middle, only slightly effected by the type of Bribe tactic. High loyalty and Low honor would lead to a little more magical defense and a little less bribery defense, however the amount of difference would be small. In essence, the Low initiative hero's land in the middle of the Grid and are rather boring, although they have the advantage of being reliable *on average* ... probably not the best person to dedicate a super-stack to, but in general your basic uninsteresting hero ... as far as a bland personality. He kind of cares which nation you declare war on, but not enough to significantly matter.
High initiative Champions, other than having strong personalities and being very Peculiar (having widely diverse abilities, having a widely diverse and Quirky personality) are also better leaders of men ... better organized, farther forced marches, stronger troops. Also, even if they do Withdraw, retaining champions will take less of a loyalty hit (if at all) and less troops will disband (if at all). Also, if we still have an "evade" stat, if your army is defeated/routed, a Champion of high initiative will have a higher chance of getting out of combat alive, with more returning troops (a route will result in a more organized fighting retreat, and thus a larger portion of your army will survive the route as opposed to getting routinely slaughtered by the opposition).