Mourinho. I mean its obvious when you think about it, isnt it? United has been utter shit last year and there is absolutely no way Mou could do worse than that considering the signings United made. Everything above an EL place will be a sign of progression. United fans dont need to see an immediate PL title, its already enough if United sinply looks like a team again that can be in the race for it. Thats enough, and with the squad he has its alnost fool-proof. Even Tottenham can do that. Meaning that all Mou has to do is simply not being shit, and he'll be considered a success.
Pep meanwhile has to win the league. If he doesnt then people will say stupid shit like "I always said he cant do it in a proper league" etc. Pep has always been critisized for almost unfairly ridiculous stuff, it will not be any different in England.