You both could be right, but to be honest, I think the move does make sense. What else were they supposed to do?
They tried going for a manager, with a good reputation (at the time) and was doing well on a meagre budget, at the behest of SAF in David Moyes. But he took them from league winners to 7th place. Lasted all of 10 months in charge.
Then they went for a multiple-league and European cup winner Louis van Gaal. That didn't work out either.
So they then went for the big name - Jose Mourinho. Whilst he had a shocking end to his Chelsea tenure and his reputation was somewhat dwindling, he'd just won the league the season before he was dismissed at Chelsea. Also, his name was still synonymous with winning trophies. Surely, this one couldn't go wrong....but it did.
Every option they have exercised thus far hasn't paid off. They tried going for SAF's recommendation - it flopped. They tried going for the big names, with trophy-laden careers, and this wasn't good enough, either.
Surely it makes sense to bring someone in who understands the fabric of the club, connects with the fans and knows what it means to be at Manchester United?
You have to remember they've not just signed OGS, but Mike Phelan was signed as assistant manager too, and he was very popular/well-respected at the club.
So it's the whole set-up that has changed and so far, they are reaping the rewards.