Suppose skinning isn't quite so big an issue here. I'm inquiring after the effects under the skin.
Am aware Darth Sion has it for the portion of his face missing its flesh, one of the male heads (Buzz Cut) has it with the scar over one eye. This female with a beauty mark.
Not going to even pretend to know what I'm talking about here: I've observed it's something to do with what's under the skins to give an appearance that shows outside on one side of the face/body/etc and not the other. Force sensitive armors use it as well because their leg/shin guard area are asymmetrical, for example.
Recalling attempts to replicate Anakin Skywalker from ROTS, there was difficulty encountered with applying the eye scar. So would this not run into similar difficulty here? Difference is it isn't really adding anything, it's moving and tweaking what's already there.