I think that Pernell had better defense than Mayweather has now, but not Mayweather's old style. Also Pernell would be picked apart by Mayweather's speed which is way faster than anyone who ever fought Pernell. Oscar Dela Hoya was able to land on Pernell a few times, and Mayweather is much much faster than ODLH ever was. He would counter Pernell or lead and be to fast. Its like James Toney could counter almost anyone in the world even Nunn, but when he fought RJJ, Jones was just too much faster for him to counter at all.