Well you could say the same thing about Hopkins. His biggest wins were against blown up WWs and JrMW in Trinidad, Oscar and Wright. Then comes this green up and comer with hardly 20 fights and beats him twice. Still he is considered a top 5 MW all time.

You have to take many things into consideration. His long reign is very significant and some people down play or disregard the greatness of a champion who can consistantly defend his title.