Great theory but it doesn't explain why we see several managers play the same tactics wherever they go, no matter what players they have available to them. Can Moyes change his tactics and do it effectively? Only time will tell and that's the gamble Utd have taken because if he doesn't change it's not going to be pretty.
People don't like change.
With the depth and quality of squad Man Utd have it will make no difference what tactics he uses, he'll still grind out results and win trophies.
