The shading on the regular Arkantos model is off. It is generally too dark and has patches that are solid black, only his skin, pauldrons and spear are unaffected.
I looked at the textures and experimented by replacing them but the shadows persist. My guess is that the vertex normals on the model are wonky.
Arkantos with white unit color looks gray and several of the skirt panels are solid black. Compared to Kastor his general shade is a lot darker.
Because new users can only post one picture per post…
Again he is darker than all the other units except for the skin, pauldrons and spear. His breast plate should be a lighter shade than the pauldrons according the the UI art.