Toney of McCallum II fight vs. Hearns of the Hagler fight at MW Toney of the Littles fight vs. Hearns of the 2nd Leonard fight at SMW Toney that had those tune-up non-title fights before Roy vs. Hearns of the Andries fight at LHW
Hearns has his best shot at 160, as Tommy was closer to his best than was James, though Hearns may have been a little past his, while Toney was approaching his. Hearns can win if he fights a disciplined fight, using his jab and maintaining distance. The Hearns right hand would probably be a liability for Tommy; drawing right hands and countering them is what James Toney does. And he can take on and try again while Tommy can't win that game of Russian roulette. Hearns had a tremendous left hook to the body but, again, if he gets that close he is taking chances. Toney countered hooks to the body very well with a right uppercut, to the body or head. By the time he hit 168 he had very refined skill in this area, and he hit the body hard with his left as well. Trading to the body is another war of attrition that Hearns probably wouldn't win.
I see it similarly. I wouldn't count out Toney at 160, but i'm going with Hearns. As the weight increases so does JT's seasoning and the less effective Tommy becomes. I don't think he could control the fight in his usual manner. Toney didn't "like" to lead but he could when needed and that body is available as too.
I think James nails him like he did Nunn. While down. Hearns has the jab, style and speed to be a bad style for Hopkins, Jones and Toney, he just didn't have the chin and, likely, stamina.