Marvin Hagler - a legend at MW. At 175 rematch against Hearns or against Andries I would have bet on Hagler, but against Michael Spinks that would have been a big call. What about the old CW division. You would not put him near a Holyfield, but what about Carlos De Leon or Dwight Muhammed Quawi? Ricardo Lopez - Straw weight & brief light fly weight against - Yuri Arbachakov @ Fly? Gerry Penalosa @ Super Fly? Wayne McCullough @ BW?
Hagler was too small to beat a good 175lb champ IMHO. Spinks was the man at 175 for most of Marvins middleweight reign and I don't see him being able to win that one. Hearns came to 175 after Hagler had retired, for most of Haglers fighting prime light heavyweight was a pretty (very!!!) stacked division. Spinks, Qawi, Saad, Lopez, Galindez, Conteh, Muhammad etc etc. I don't see him beating Qawi or DeLeon at 200lbs (or whatever the limit was back then, 195?).
Hopkins has no Spinks, Qawi or Saad on his record, other than a good win against Tarver theres not much else on there at 175 (no disgrace Hops is an old middleweight) Lopez might be alright up to Flyweight but someone like McCulloch at bamtam would eat him up.