McCallum and Hagler are no goes. Like Winky and Hopkins. Tommy is like Tito, the big puncher who's era just stays a year or so ahead of his. Curry would be like his Judah, p4p boxer gets massively upset before his fighting heart gets called into question and he goes on an inconsistent run, he may face a faded version but not a peak version. Leonard would be like his De La Hoya, he might out point a badly faded version but more likely is Floyd's prime is during Leonards retirement. As I said, he would be a huge success in this era and he would face faded version of most of these bigger guys, but he'd have a limit at some point. When Floyd moved up from light welter the following where the big names: Judah, Baldomir, Margarito, Williams, Cotto, Oscar, Mosley. He faced all bar two, I imagine it would be similar in the 80s also.
Kevin, it's obviously fair to say you know/admire Mayweather more than I do. (still think he's a great fighter) but off the top of your head, or even if some research is involved, do you know how many fights he was in in which he was clearly the under dog going into the fight?