A defensive midfielder who can make basic passes and stop attacks, and a deep lying playmaker who can dictate the game. Bruno, Pogba and Van de Beek are all fine for a more advanced playmaker, Mct and Fred works fine as box to box midfielders in games where you can't afford to play a more advanced midfielder and need a higher workrate. However the archetype player every team needs are players we do not have.
We have plenty of specialists for that single midfield slot that tend to change on a game by game basis, but we lack the midfield spine that enable us to control games and keep tight. It has been an issue for years, but despite numerous signings we are no closer to fixing the issue. We would also do well to have backup to this spine should we face injuries.
Out: Pogba, Van de Beek, Matic, Mata, Pereira, etc
In: Neves type, recall garner, Ndidi type, and backup ndidi type.
Leaves us with a nice stable midfield:
The 10:
Bruno/Mejbri
Neves type/Garner Ndidi type/backup
Workrate:
Neves type/Garner Fred/McT
Ndidi type/backup
IMO we need three new midfielders before we have a functional midfield combination.
I don't think our defence is as terrible as it is made out to be, and our front three has tons of potential and ability. However, midfield is just a gaping hole at this point.