I'm in direct disagreement with most posts here. Most seem to think we need more CBs and CMs or AMs.
For example this...
If we walked away from Dortmund's demands I'd guess we could sign the following three players with the kind of structured deals that Dortmund won't entertain.
Grealish
Torres
Brooks
How would we feel about a window like that, or is it Sancho or bust?
I think it would be acceptable.
... would be a complete failure of a window in my book.
Firstly we need more quality options in attack. We only have Ighalo till January and arguably Ighalo's not trusted by Ole considering how reluctant he is to bring him on even when Rashford is having a shocker. Grealish is not an attacker, he's a playmaking type of an AM too similar to Bruno and Pogba. When Ighalo goes, we have no #9 sub for Martial. We have to shift Rashford up top and play Dan James left. The latter is the only player to replace Rashford or Greenwood as a forward threat. That's beyond abysmal. We have neither enough bodies nor quality once Ighalo goes and we shouldn't wait for him to go before solving that problem.
Secondly we need a left footed LB to compete with Shaw and provide cover when the latter is inevitably injured again. Playing with a right footed LB in Williams really narrows our play and significanlty reduces our penetration down the left. We also need competition for AWB at right back because quite frankly his attacking play and defensive positioning leave a lot to be desired. If we're not signing a RB this year (most likely), Williams should be competing with AWB while the new LB competes with Shaw.
If Mata, Lingard and Pereira are to be moved on we could certainly get another AM like Grealish to cover for Bruno. But it's only 3rd in the list of priorities because we could keep one of those for another year or we could play Pogba at #10 and McT at CM, when Bruno is out. So while it's "nice-to-have" it's certainly not as important as the above two.
DM for me is not a concern. We have Fred and Matic and as last resort McT again. That's plenty of cover and plenty of quality. CB is almost the same. Behind Maguire and Lindelof we have Bailly and Tuanzebe, with Mengi starting to break through as well as Smalling perhaps if he's not sold. And that's assuming Rojo and Jones are finally shown the door. We could spend huge amounts on a new CB and not see a material improvement on our current players.
So for me FW and left-footed LB are the priorities with an AM coming in 3rd. If we buy CB, CM and AM it will be pretty disappointing.