I suppose that the picture depicts a hastatus on the right, a veles at the bottom and a principus on the left. Or is it a triarius without his hasta?

Centurion on the left....Hastatus on the right...Velite on bottom.

Thanks

The only thing really marking out the guy on the left as a centurion is the fact his sword scabbard is on his left side, something usually only centurions (and ranks above centurion) would have. He is missing his "vitis" (vine staff), his decorations/insignia, and his transverse helmet crest, though the latter two appear to have been non-standard anyway.

In any case, brilliant work as always Mr. Shumate. Love your artworks! Keep up the good work!