Absolutely, he is correct.
Of course, I agree/disagree with him, it depends. Maradona was talking about who is more entertaining; Del Piero Or Zidane?
But when comparing between any two players, we have to determine the points of comparison precisely. For example, for anyone to say that that player is far the best player ever, I find this very delusional and inaccurate.
In my opinion, Maradona is the best player ever, but I don't agree with myself when I say that. Simply, because I do believe that a football team is formed of eleven players with different positions and missions. Most of the football fans measure a player's abilities depending on his ball control, a thing which isn't fair by any mean. For every position on pitch its required skills.
Consequently, I have to compare a centre midfielder to a centre midfielder, a right back to a right back and so on...I prefer to say; Maradona has been the best playmaker ever.