Heath's clearly got the best combo so predicting that he will do well isn't very challenging. The only thing left for him is to improve a few weak points, at which point he'll be closer to untouchable.
Greene's got the best chance IMO, because he's not only packed on more size he's also got exactly the dryness Heath doesn't have and will win on posing as well.
Jackson was a winner in a weak year, it was really Vic's to have and he lost the chance. Jackson can't take it to another level like those other two.