Finally got around to adding in Spine's really solid skin system and applying it to the default enemy rig.
Because the heads are all slightly different (and have different bones and animations) I had to kind of work around that by creating and attaching empty blank images to the skins for inactive heads. Im sure there is a better way but a brief search didn't reveal anything and we are on a deadline! This seems to work, but I'd love to know about other approaches.
Next step is to create a "Caster" / "Shaman" version and add in some more general use animations.