Ahhh..lol. Yeah, I fixed that line for the Sov on mine. That was a case of a old file getting in where the new file should have been. It's what happens when you edit files in multiple folders at once.
Ok, the skin showing up on other factions is a side effect of my first version of the skins. Here's how you fix what I didn't clean up there (which Is cleaned up for the next update).
Go to your directory here: Documents\My Games\Elemental\Units
Open up the file: CoreSkinsUndeadZombie.xml
You'll see this:
<DisplayName>Undead Zombie Skin</DisplayName>
Take out All the lines that say "<SupportedUnitModelType>" and replace them with:
What this will do is stop the zombie skin from showing on any race but the "Undead". What this means though is if you want to make a Undead Sov then when picking the race you'll actually have to pick "Undead" or it won't show up. This also applies to making a new faction using either Stardock's Faction creation tool in the Workshop or using Murtea's excellent Faction Creation Tool. Either way though if you don't pick Undead as your race you won't see the Zombie or Skeleton skins.
I'll make sure all this stuff is tightened up in the next update. When I finish making the rest of the custom Undead City Tiles I'll release a 2.5 Update. When we can get Admirals Skeleton Model animated and in game we'll be releasing Undead Rising v 3.0 with "Real" Skeletons instead of just my costume skin and it will include Undead Females as Vampires. Right now Undead Females are disabled but for some reason the zombies carried over the female sounds which is fixed and will be in the 2.5 update as well.
Hope that helps my friend