Was Rod Laver the best tennis player ever? Or did he simply excel in an era when the competition were not very good?
He was a fine tennis player for sure, but wouldn't get a set I think off Federer, Nadal, or (in his prime) Jokovic.
So when trying to decide who's the best ever, who they were up against at the time is an important factor. I am not suggesting there were no good opponents back then. However, from about 1992 onwards, when the first ball was kicked in August, you could be pretty sure it would be United lifting the trophy in May. From 1992 to 2003, United won it 8 out of the 11 times. Was that down to the fantastic teams United had back then? Sure it was, but it was helped greatly by the fact that other clubs were all over the place.