Two seasons with Arsene Wenger and I'd put any money you like on him being one of the best and most consistent players in Europe.
I rate Gerets and Deschamps fairly highly as managers and they couldn't do it either.
Tbf they did. He was just a troublesome (behaviour) player but contributed to title wins 5 years on the trot with both those clubs iirc.
If Wenger or any other manager at that level thought they could make him consistent, they'd probably have bought him.
Stop it.