BoxRec

If Marvin had met and beaten Hugo Corro, would his career have been for the better or for the worse?

No different.

I can name only two fighters, who really would be able to defeat the Marvelous One. That's Leonard, who had actually done this and prime Duran ( as for me,Duran had already been past his best in his fight vs Hagler).

Corro was a decent enough fighter, but I don't see Hagler's reputation or legacy changing in any way by being able to defeat him.

Corro would have been viewed as just another Hagler victim. Along the same lines as a Hamsho or Sibson.