I enjoy the art style..
but he looks alot like Broadway from Disney's Gargoyles.
Like you said, there is no actual set rule for an Orc, but I thought the resemblance was uncanny.
Also, as for the fat. Yeah he's fat, but he's packing under the fat. I mean, look at a Sumo wrestler. Under their fat stomachs are very strong muscles, and I've seen one punch a door our of anger and snap the thing in half (it was an interesting stay in japan xD ).
Anywho, Awesome picture.