i don't think there would be a prime for prime fight for this match-up even if they are of the same era.
Sugar Ray Leonard would KO Moneymay in 8 rounds or less. No chance of a decision. If it was a 15 rounder, Floyd would have permanent brain damage.
Sugar Ray wins, probably by late KO. Look at the names on his resume. Leonard beat Benitez who was better defensively than Mayweather is. He also beat Hearns, Halger, Duran and Kalule (underrated win IMO). Mayweather would be able to slip a few punches, but over 15 Ray would get through with his speed. He also had very good power, power which i dont think Floyd could take for 15 rounds. Leonard TKO 13
Sugar Ray wouldn't KO Floyd. That's bull****. He would win by UD. Great big man will beat a great little man.
Leonard., any day of the week. By stoppage or decision. Very few welterweights I would pick against a prime Leonard.
Money is easily the best boxer of his era skill and resume-wise and he's certainly an all-time great, but old man Mosley was able to crack him twice and hurt him and would have made for an interesting fight with Floyd in his own prime. Sugar Ray was on another level entirely and had a style and speed that would give Floyd fits. Ray was a boxer/puncher of the first degree, had a first-rate chin to fight when he needed to, and Money May has had trouble when being pressured (Castillo) and matched with speed (Judah) in the past and neither of those fighters bring what Leonard brings to the table. Leonard by late KO or clear UD. And Robinson would have murdered them both.