Tarver by close but unanimous. Tarver just a little to big. But Hagler makes it uncomfortable for tarver all the way.
Tarver would come in around 185 lbs + and Hagler around 170 lbs. Probably by time enter the ring Tarver 20 lbs heavier. See what a difference this makes watch Golovkin vs Jacobs. Tarver not aggressive opponent so Hagler would have to force the action . Tarver would get on his bicycle and clinch when Hagler catches him. Combined with Tarver size this would be a snooze fest. Tarver on points.
I don't think light heavyweight would agree with Hagler...but with that said, Hagler could possibly come in lighter and retain his mobility. I can't see Tarver stopping Marvin...and Marvin would not coast just to lose a decision. I think Hagler could do it. Hagler by decision.
Whilst Hagler is clearly a superior fighter to Tarver, he would only be allowed to weigh 160 pounds in this fight whereas Tarver is allowed to weigh 185.