Moore started out at middleweight. But he did the most work at light heavyweight and heavyweight. Hagler was one of the best there was at middleweight. Remember, Moore stopped Bobo Olson. Could he do the same to Hagler? Could he prove that Hagler was only semi-marvelous rather than Marvelous?
Why do you not describe at what weight? If you do not specify do you mean where each was at his best in absolute terms? If so then Moore at HW had about 30 lbs. on Hagler & would fairly easily defeat him. At MW I do not think Moore was accomplished & Hagler wins.
At middle, Moore would have still been raw, facing Hagler may have being a little to much. I'll say Marvin by late ko.
Archie wasn't prime at MW. At 168 or 175 it becomes much more interesting. I don't think Archie was at his best until he hit 175