They wouldn’t necessarily all be mixed. You could have it depend on how close to Orcish territory the undead are placed on the world map, or when they beat them in battle. So you’d get pure and mixed groups. Humans would still be the majority though, since these are human lands and so more dead humans would be available to work with. Just imagine the occasional undead Orc Chief though…
It seems to me like a unit like this would be easier to add than totally new units, since many of the mechanics are similar to already existing units that are tried and tested. The skins would probably take the most effort to make, since you need to add a lot of those to make it work – unless you do the ol’ ‘all Orcs look alike anyway’. :P I can see that being the biggest problem, since I can imagine that Psen already has a lot on his plate.
