I see both breeds quite well on him; my first thought though is that he REALLY needs to lose some of that weight!!! Hard to tell just how lovely he is with so much excess chub...plus that is really really hard on those legs of his...compare his body to his legs...BIG difference, and you could be in big trouble should he founder, or start developing navicular, arthritis, or any other ailments that can be brought on due to all that extra weight he wasn't designed or built to carry.
Over all, I see a decently built horse (albeit very very fluffy), he has the nice araby head, and neck, higher tail set, and nice compactish build (traits from both breeds). He has a soft eye, and appears to move nicely. I would love to see him with about 2-300 lbs less. He would be stunning, I think.
Right after the first pictures she started working him out (finally, he had been on pasture for I think 3 years) and the last few pictures he's actually a lot smaller than the year before but you are exactly right, he did
start to founder this Spring and that was the wake up call she needed. She decided she either had to sell him or start riding again. She didn't want to sell him so she started riding and she managed to get herself out of a 7 year depression!! It's crazy what horses can help you through.