How highly would Mayweather be rated if he accomplishes the following feat?

[Taeth]

1. Defeats Mosely

2. Defeats Margarito

3. Defeats Cotto

All in consecutive order then retires. How high would he be ranked? Can he be a top 5 all time great?

I don't think this would change that much in all honesty. Will people really ever put Floyd above guys like Duran, Benny Leonard, Billy Conn, Ezzard Charles? I doubt beating an old Mosley, and two unknowns in the historical sense will do much to raise his stock. I mean Wright beat Mosley and it much less to enhance his stock then beating Bernard HOpkins will despite Bernard being 43.