I agree he would have been a fantastic heavyweight if he kept in shape, he should be below 230lbs for his height.
Guys like Arreola and Solis are one of the reasons there should be a super heavyweight division (with heavyweight maxing out at 225-230). Without a weight limit, it's easy for these guys to rationalize bulking up so they have some extra size against a Klitschko or Lewis type. But if they had to get to 225 or 230, then their trainers would have a better basis for imposing discipline to keep them in shape.
He couldn't fight at crusier. It wouldn't happen. He's not the first guy to put on weight compared to his Olympic weight.