Yes this is easy: Hagler at 160 (decision) and EMM at 175 (possibly KO, we just don’t know how Marvin would stand up in that division to guys so much more naturally bigger … and Eddie had some pop.
Eddie was "around" middleweight for 21 fights. In his 15th fight he was leading prime Bennie Briscoe before Briscoe came back, aided by a cut to win a split decision. This is an exceptional performance at that career stage. You have to take peak Hagler over Eddie, that's a given. Match them fairly at the 15-20 fight stage however, and i am taking Eddie, absolutely.