That defense evolved though. Expertly I may say, but it never changed dramatically. Once he lost more than one player at a time he lost it for good. Bold denotes new player;
1998 - Seaman, Dixon, Keown, Adams, Winterburn
2000 - Seaman, Dixon, Keown, Adams, Cole
2002 - Seaman, Lauren, Keown, Adams, Cole
2003 - Seaman, Lauren, Keown, Campbell, Cole (Toure/Keown shared a spot)
2004 - Lehmann, Lauren, Toure, Campbell, Cole
After that...
2005 - Lehmann, Lauren, Toure, Campbell, Cole (Cygan & Senderos both played 12 & 15 league matches mind)
2006 - Lehmann, Lauren, Toure, Senderos, Flamini (Cole injured, Cygan played plenty)
2007 - Lehmann, Djorou, Gallas, Senderos, Clichy
In 2 seasons he took a defence that had evolved one player at a time for over a decade and was left with a shower of shit. Gallas was 100% great but everything else there, including a 40 year old Lehmann was dogshit.
That said, as I've said plenty elsewhere, Wenger is a genius and a top manager. He just isn't going to go down as one of the greats that had longevity at the top.