Both agressive technicians when young who then gradually turned into counter puncher types. Both have functional jabs, though not great ones, are well rounded in their punching but probably have the right lead as the most dangerous weapon, are great defensively, uses economical footwork etc, etc. They also incorporated unusually much physicality (and fouling) for such technical fighters and relied very much on their impressive physical strength and stamina (before they got old). They were both brawling technicians, in short. I'm not saying they're carbon copies or anything, but I see some clear similarities.
Hopkins was just so damn good at utilising his size and strength. Clearly better than Hagler, I'd say. And Duran at MW didn't really have the mobility to get out of the way consistently when Hopkins would have slamming into him behind that lead jab. I think he would make it partly into a brawl and wear Duran down. Don't think Duran had the power at MW to put him off much either A late stoppage wouldn't surprise me.
hopkins by decision, but Duran might give him a little trouble, but Bernard would be too fast and win a decision. Hopkins would probably have his best success with his right hand with Duran and might actually swell up Duran's face, and Duran would be reduced to lunging and barely making the 12 rounds. Not a wide one decision ,but a comfortable one. Hopkins reach is I think 75, like Marvin Hagler. Leonard's is 74. Hearns reach is 78
Please, Duran is not a middleweight. The only middleweight champs Duran has a chance against are in your face stationary types that are there to be hit. I reckon Duran vs Hopkins would look somewhat like Marquez vs Mayweather.