I see McGinn's name mentioned in here a lot. I really like the guy, but don't think he'd improve us that much. He'd be a poor fit for the players he'd playing alongside.
McGinn is good at late runs into the box and high risk/high reward passes in the final third of the pitch. His workrate would be a great match, but his ability to protect the ball in possesion and play line splitting passes isn't good enough for what we desperately need.
Unlike City, United don't have any creativity in the frontline. And unlike Liverpool, we don't have any end product at LB or RB. United's only chance of building a functional unit from our current squad is to pack the midfield with playmakers.
McTominay can do it over short distances at a high tempo (just don't ask him to be our Xavi like he tried to be today). Pogba's passing tempo needs to improve, but I think he has the potential to get there. Fred, Pereira and Matic are nowhere near good enough. McGinn wouldn't be either at the specific qualities we're lacking in the middle of the park.
You're right about McGinn's strengths and weaknesses but I'm not sure I agree about his being a bad fit with us, if we assume the first XI should look something like this after January:
----Rashford-----Martial-------------James
---------------Pogba-----
CM---------------
------------------McTominay---------------
LB--------Maguire---Lindelof-----WanBissaka
Martial is basically only being good at dropping deeper and wider and getting the ball to his feet so we need a goalscoring midfielder who can get into the box to fill that space and take advantage of his not being a target man. And if Rashford is on the left then James is going to be playing quite wide trying to get crosses in on the right rather than coming inside constantly.
And Pogba needs a partner who works hard because he sometimes doesn't seem to do that for us.
I'm not saying McGinn is perfect but he does make a lot of sense as a compliment to our talented, mercurial Frenchmen.
I assume Pogba will leave this summer and in that case we should just buy a couple midfielders who are better in possession than McGinn, but for January to the end of the season I think McGinn would fit pretty well.