I expect a United manager to say "next season without a doubt we should be fighting for the title, everything else would be a total failure."
Guardiola said a couple of days ago "This team won the treble, if I don't reach the CL fianal with them it will be a failure."
Moyes will never ever take United to the very top, for this you need a manager with complete opposite attributes to those Moyes possesses, and that's the big problem. You just can't completely change someone, let alone someone in their 50s.