Yeah, Sir Alex naming Cantona and Giggs in his four world class players is an odd one considering some of them he left out. Giggs was just longevity. Think the definition he gave and reasoning for picking them wouldn't quite go with the standard definition of world class.
Overrated retired players. Hmmm.
I honestly think Ronaldo and Zidane are in that list.
Beckham. But then I think he was overrated during his career too.