Duran was really good at middle at 38-39, while McCallum troubled a much better fighter in the form of Roy Jones at 39 in the super-middle division early on in their clash, while SRL was awful vs Norris at 34 and even worse v Camacho at 40, Hagler was slowing down coming towards his mid 30`s while losing to Ray and Hearns was completely finished by the age of 39, so who would you pick at any weight that could meet at?
Hearns and Duran are the only ones with any form. Duran had Barkley around that time. Jones won on all three cards 120-107 and as many suspect took it easy.
I would say Hearns at Light Heavy but Manny Steward would not let Tommy near McCallum. McCallum is one of my all time favorite fighters. He one of those guys like Ezzard Charles that are just a joy to watch. We are lucky as fight fans to have been able to see the Toney/McCallum trilogy. A truly amazing fighter.
Duran would give McCallum all he could handle on the inside. Question is at 39 would McCallum be able to get out of Dodge and do a punk ass Ray Leonard impersonation? That was the way to beat Duran at that time but McCallum was no longer snatching bodies at 39. Duran could beat him if he was in shape like he was for Iran Barkley. Hearns had a chin/leg issue when he got into deep water. McCallum didn't have enough pop though at this time age