While Mourinho was clearly not helping himself by the end of his tenure, and they have some good players, for the amount of money spent, they should have a lot more great players. If Utd are smart, they are cleaning out the front office and handing control of football matters to a sporting director. That guy would want to hire his own coach. Bringing Solskaer in to hold the fort until that person has their feet under the table would make a huge amount of sense.
If they do go down the sporting director model, would Poch want that? He has some say at Spurs, and not much money - surely the only way you get him to leave for Utd is if they offer him a pile of cash to spend on players, and control of who it is spent on. He has a good thing going at Spurs right now, but if spending is constrained by the stadium, will he actually get to take on the likes of Citeh and Liverpool there, or will he have to keep making do? He's never won a thing as a coach, he could do with getting some trophies on his CV. Also, Real are going to be coach-shopping in the summer, and that's a pretty good place to collect trophies - that might look more attractive than Utd...