Not sure where the idea has come from that Zidane wasn't productive from a goalscoring/assisting standpoint, he got plenty, probably a combined 20+ each season. Same goes for Nedved.
The best way I can put this is by pointing at Bergkamp. He was great at getting us playing well after 2002 and his value to the side in the following seasons, including for the invincibles can't be disputed despite an average output at best, but you're mental if you think he was just as good then as he was in his first few years here.. once he got going.