Gutter Boy
Tim Sherwood
I agree with your overall point that we need players that are an absolute perfect fit (or at least a very good fit), quality not quantity. Someone more experienced in central midfield who is also very good on the ball. Schneiderlin, Cabaye (or arguably Carrick) could be vital. But bringing in someone that's not quite good enough could hurt the development of those younger players and I would rather just see us be patient with Masonleb.
Other positions someone to "fill the gap" might be more apt. Like many here I think replacing Adebayor might be a good idea. We don't necessarily have to replace him with a "perfect fit" player at this point in time, an option to Soldado and Kane could be valuable even if more of a squad player. Perhaps someone versatile like Jay Rodgriguez,
I think a big theme for this window and the next will be cutting numbers.
We will need to add a CB (Moreno), CM (Schneiderlin or Cabaye) and forward (Rodriguez), but we'd also be clearing out 6-8 players (Kaboul and Chiriches from CB; Capoue, Dembele and Paulinho from CM; Ade and maybe one of Townsend or Lennon from the forwards).
If we move towards a tighter 22 man squad which includes (rather than excludes) the academy graduates, that's giving them a clearer run to the first team and more game time when they get there.
So Mason and Bentaleb would become 2 of our 4 CMs for 2 positions, whereas now they are 2 of our 6.