Regardless Pogba stays or leaves the team, Man Utd needs good players for their midfield and that's a fact. Indeed Gravenberch is a good option not only because is young hot talent but also because his presence can "trigger" a better Donny van de Beek.
Yep. Man United midfielders aren't strong enough, they need some changes in this line. Actually, Man United has many midfielders, even some of them are top players such as Pogba, Matic, Fred, and Van De Beek. Unfortunately, they cannot play solidly and seems no chemistry among them. Man United management needs to evaluate what to do. If it is necessary, they may rebuild again this line by selling some current midfielders and buying some new players. Because of this reason, I really support the idea to bring Gravenberch or other top midfielders. But Man United also needs to balance their squad by putting some current midfielders on to transfer list.
Manchester United does have a lot of midfielders, but only Bruno Fernandes is the only one who is consistent and his performance is quite good. Man United's midfield really needs some serious attention, they've had half a season already, but I think Man United's midfield performance is still far from good, so selling some players and signing some new players is not a bad idea.