What he lacks is the ability to adapt what worked for him then into today's game.
Plus there is an age consideration with the exception of Ferguson, how many managers are winning the top prizes well into their sixties, as you get older especially you lose the ability to innovate and lose the spark to tear things up to begin again.
We compare Wenger to Ferguson and say it comes down to an appetite to win, but also Ferguson knew his limitations he was a great motivator but he also knew that coaching and training on a day to day basis should be left to younger men. Wenger simply cannot do that, even though it was Steve Bould in the dug out next to him was Neil Banfield who had Wenger talking in his ear every few minutes.
We know that there was a power vaccum in the club structure when David Dein left and who stepped into that vaccum none other than Wenger himself and no one tried to stop him, and this is what we are left with a man who has made himself Unsackable because no other manager would be prepared to do half of what he undertakes.
Ferguson sure as hell didn't have the same power and influence at United that Wenger has at Arsenal and you could argue even that has been detrimental to his management, because no more do you have anyone who can take Wenger aside and say "Arsene you're doing too much you need to let others take responsibility" it's abundantly clear Ivan Gazidis cannot do it because he's in the unique position of being hired by the man over whom he is meant to have ultimate responsibility over.
Football ultimately has changed, Kenny Dalglish won titles with liverpool and a title with Blackburn but we know he'd be incapable of putting together a winning team even with the kind of money he had at city or United, the same with Louis Van Gaal does it denigrate what they achieved in the past, no it just means that their time has passed.