Fergie always seemed to plan two years ahead whereas rival clubs could only really concentrate on the season in front of them. This is why he always ended up back ahead of the game.
Approaching retirement and under pressure from local rivals City, something changed. Fergie couldn't countenance retiring in 2nd place, he poured everything into one last effort, squeezing the last drops out of an aging squad and buying van Persie.
Of course Moyes made a balls of the window and the players didn't buy into his methods and so on, wasting another season, but the bottom line NOW is that United are 2-3 seasons behind where they normally would be