Hmmm, he is definitely an elite level athlete and martial artist but i don't know about this one, i can see how having one arm can be a disadvantage but it can also be an advantage like in the video of him winning the XFC title, i don't practise BJJ but imo the guy was trying to fight Newell's hands to release the choke but there is no hand there also arm bars and omaplata's on his left side and certain transitions would be impossible. So tbh my conclusion would be that; no he should not be in the UFC...