I've got GW LotR figures, mostly goblins and elves.
If my goblins are largely spear (no shield), sword and shield, and bow, and my elves are mostly spear and shield, sword (no shield), and bow, I think I'd need to be able to distinguish these sides better to have a good experience with Havoc. There is more difference between an elf with spear and shield and a goblin with a spear than just the shield.
I don't care for special rules per figure or army, because you have to invent more when you add an army, you don't know in advance how they'll interact, and you have to read the rules for the army to know what to expect. But I do like having standard abilities that can be applied across armies to distinguish them. So maybe I'd like One List plus a set of attributes to choose from.
I more easily swallow the idea of one list with larger bodies of troops, like in Hordes of the Things. You figure numbers evens out quality.
andy