The comparison to Ferguson is utterly ridiculous. Ferguson stayed at a very rich club for a very long time, a club much richer than its rivals, he won a lot of trophies.
But no one talks about his mode of football today, no one tries to emulate the style of 1999 and not just because football has moved on.
He was not an innovator he was a mechanic, constructing a well oiled machine over many years, he won a lot of stuff, then he fucked off and left little behind, beyond screwing the club he purportedly loved. No one studies his tactics today, he brought nothing new to the game and he left nothing behind.
With the exception of a few sycophants in the media he's been mostly forgotten.