There's no doubt Floyd was tremendous at the weight. A number one ranking is fair. It's hard to know how he would do against the other empires of the division though. A unanimous decision over Arguello seems like the logical answer, until you consider the latter's timing, and the fact his right could make Floyd's legs do something we haven't seen before. Make it fifteen and you've got a beaut. And let's not forget Kid Chocolate. His talents would crossover nicely in this era.
Mayweather at 130 was so far from what he has grown into; the 130 Mayweather gets stopped in 8-10 rounds by the 130 Chavez, kinda like his uncle did at 140, though much better than Roger's 2nd round loss at 130. Arguello is going to beat him at that weight also, knock him out. Chavez beats him at 135 and 140, too.