I never said Man U will be great again under Mourinho. But he could pull them out of the rut. Why? Because his record and success speaks for itself. He has been more successful than most managers out there in modern football. That's a fact.
Well I mean those who said Man United will be great again lol, not you.The only team that I will support is Everton. I hope they surprise the league and everyone like what Leicester did. Just don't know when is the right time though. 
Every 15-20 years, there is a small club who could win English League, like Blackburn Rovers, Nottingham Forest, and Derby County. Too bad, your team must wait another 20 years after the chance for this decade has been taken by Leicester City 