I meant brachioradialis, not brachialis up there, my bad. I updated it. Regarding the skulls, I was actually talking about the mesh resolution. Should have made that clearer. It's not uncommon to give some areas more resolution (both mesh and texture) if it's clear they'll be seen from a closer distance or have more…
That looks like a fun gnarly character with a lot of detail, but especially the beauty shots are really hard to read. The metal arm basically disappears into the body in the first shot, even without squinting. Perhaps you wanted to show the skulls, but having a stronger light from the left/back/top and less from the front…