Quoting kenata, reply 27In my eyes, the killing blow should be the logical conclusion of a tactical maneuver and the shifting of battle momentum. By making the killing blow equate to strengthening units for the long term, the player must gamble units instead of focusing on solid tactical play.
And that is why it is interesting. There is risk, cost, and reward involved to make the desicion situational and not something to do without thought. Having the safest path always be the best is boring and leads to battles frequently falling out in exactly the same way.
Age of Wonders is more suited to making it interesting as its machanic make it so you think about more than than if your unit can kill the target and if the target might kill your unit. Specifically you have movement related considerations, where as in E:WoM most units do not have enough move to get in position and attack.
I'll grant that rewarding xp for something the player can easily manipulate - i.e. which unit gets the killing blow - does give you an extra risk vs. reward choice to consider, and makes combat that much more interesting. But there are many things that can be done to make combat more interesting, personally I'd prefer if manipulating which unit gets the xp wasn't one of them. As a gamer I'd rather be worrying about how to win combat, not who needs the xp - if winning isn't something you ever need to worry about and combat is therefore boring, that's certainly a problem, but there are other ways to fix it.
And this is entirely my opinion, but it also just breaks immersion for me; I picture Aragorn standing over the mortally wounded troll, raising his sword to deliver the death blow - and stopping as Frodo yells, "Wait! You're level 10 already, I need the xp!" Aragorn: "Oh, fine. See if you can hit it." Aragorn lowers his sword as Frodo stabs the troll in the shin, doing no appreciable damage. The troll makes a swipe at Aragorn, which he dodges. "Make it quick Frodo, I'm already down to half hp.."
Really I'd be satisfied with a simple xp split: if one unit kills a wolf in single combat he gets 10 xp, if 10 units kill a wolf they get 1 xp each. You'd still be able to level units that aren't especially good at killing things by letting them tag along, there'd just be a cost associated with it - the units actually doing the fighting would get less xp (as opposed to the current system, where there's no downside to bringing extra units, it's just free extra xp one would be a fool to pass up on). And once in combat there'd be no need to do anything unintuitive - like spamming an ability that grants xp or shuffling a weak unit to the front lines to get the killing blow - the player could just focus on the actual tactics of tactical combat without worrying about xp.
Assuming there are, at some point, actual tactics to consider. This would fall under the heading of "things that can be done to make combat more interesting" mentioned above - combat certainly needs something. I just don't think that something ought to be an xp system that can be manipulated during combat.