I don't think so. Hearns was a huge puncher especially at 154 where Duran fought him. Even when Hearns stopped Duran, I knew that Duran would not be stopped like that again. In round one and beginning round 2 Duran took punches from Hearns that not many guys could take. He took a good punch. What I say was his weakness was speed and being outboxed. It took some hard fast punches to stop Duran against Hearns, and Roy does not have that leverage nor does he have the ferociousness of Tommy when Tommy goes for a knockout. Roy got knockouts with speed but he didn't have the leverage of Hearns, but Duran would have taken the punches probably. Roy would have had to watch for Duran's right, but he would outbox him. One thing about Roy is he didn't box that effectively on his toes. He was just so quick with his reflexes, that most guys he fought couldn't do anything because of how fast Roy counterpunched. As for Duran, he would take Roy's punches early very well although I am not sure how long he would take punches if he were being punished by Jones into the late rounds, but I think he could. I was actually at a fight in Reno when Jones stopped Art Serwano in 1992 on the Mancini/Haugen undercard. A very scary knockout. Everyone in the crowd was like oh wow. Everyone was impressed with that sort of speed.
I'd personally pick Jones to beat everyone. I don't think Duran or Leonard merit serious consideration. Hearns and Hagler? Both could potentially win for different reasons. Hearns had the power to KO jones and he also had good speed, but Jones would likely KO him somewhere along the line. Hagler, could pressure Jones and make life very uncomfortable for Jones, and Hagler being the only natural middleweight could potentially beat Jones, but in all honesty I think Jones is just too fast and has too much power to loose to any of them, including Hagler.
Not at Middleweight. Jones was a bigger puncher at Middleweight than Hearns was. Jones and Hearns are pretty similar. Jones had great power and was a H2H nightmare at Middle and Super Middle. He was very good at Light Heavy but would get beat by the absolute best there like Spinks and Charles. Hearns had great power and was a H2H nightmare at Welterweight and Light Middleweight. He was very good at Middleweight but would get beat by the absolute best there.