It makes you wonder what the answer is.
The armchair managers want 4-3-3. They don't want McFred as it stifles creativity and their passing isn't up to scratch. They don't want Matic as he's somewhat of a liability and doesn't have the legs to keep up with a high-intensity or counterattacking opposition. McT can't play as a sole DM, Fred can't play as a sole DM, VdB hasn't done much to suggest he can take up the reigns in midfield. Then there's Pogba, the solution to all our midfield woes until he's actually put there and everyone remembers how dreadfully exposed we become. Beyond that we have Mata and a bunch of attacking forwards.
I know people like to think we can wave all these problems away with the magic coaching wand, but these are personnel problems first and foremost which the management team are at fault for not correcting.
Broadly speaking I agree with you.
Our squad is still a hotchpotch of different players. Ole has helped address that to some extent. However, it must also be admitted he has made some signings that have also made that problem worse too.
If you were starting with a blank canvass, designing a team to play 4-2-3-1, there is no way you would assemble a list of midfield options that look like ours.
I look to Bayern Munich, the best 4-2-3-1 team in the world, and look at the balance of their midfield two: Kimmich and Gortezka. In that midfield Kimmich sweeps up and starts all Bayern's attacks, next to him Goretzka adds the engine and quality to get up and down the pitch. When Kimmich is unavailable they have Roca to deputise. He's not as good, obviously, but he plays in the same style so Bayern's system doesn't need to shift. Likewise, nothing changed when Gortezka came off for Sabitzer against Dinamo. Cos Sabitzer is a similar enough player to Gortezka to do the same kinda things.
In our squad we have one defensive midfielder: Matic. One. And we only have two midfielders who do the same sorts of things: Fred and McTominay. This is despite playing 4-2-3-1 pretty consistently under Van Gaal, Mourinho and Ole. The squad construction is lightyears away from what Bayern has done.
This is not to say that with better players Ole would turn into Nagelsmann or Hansi Flick. We know Ole's strengths are not
that. But if you got Nagelsmann in a United boss, and told him you wanted to play 4-2-3-1 to suit your attacking options, I think he'd demand a massive midfield overhaul.