One very important point that needs mentioning.
Fergie, God bless him, will retire one day. Money or not, how do you replace him?
If I had a worry, this would be the nightmare scenario. This could already be in the pipeline at OT.
Fergie to retire when Mourhino's contract runs out at Real, and he becomes United's new manager. Around the same time, the Glazer's sell United(£1-2bill) after clearing large chunks of the debt, to some Middle East or far East billionaire.
Mourinho + hundreds of millions to spend on players is a scary thought.