Which fighters in history are rated too highly?

I believe some of you don't want to rank Greb because he is white. Jack johnson, Mickey Walker, Gene Tunney,Jack Demesey were all great fighters who either fought or sparred with Harry. They all said how great he is. There's also no film of ancient Rome but I know it was a great empire. Your arguement is invalid. Having said that, Jack Johnson is by far the most overrated heavy weight who ever lived.