I want to give common mobs 'overlay' textures just like how horses have interchangeable patterns. It's only going to be a resource pack, so I want to make use of random entity textures/models by just copy+paste the body, make it slightly bigger than the original body, and use that for a pattern. I'm aware that in game they will be completely random and not genetic like horses, It's only supposed to be cosmetic.
I've tried manually changing a body part's size from 12 to 12.1 but it won't allow me to. Is there a way to fix this?