If I consider the next year, lets say we have a budget of 350m (I think spread out over two windows is a fair budget).
3 attackers - Liam Delap, Omar Marmoush and Jonathan David
Would probably cost 125m (David is free but would demand a signing bonus)
1 defensive midfielder - Ederson.
Would probably cost 75m. I think the problem with Rodri out is that neither Gundo or Kova are good enough, we really only need 1 more player, as we have loads of options on who can play as the #8 (Grealish, Nunes, Lewis), and I think that position is fine, its the #6 spot thats killing us.
4 defenders - Robinson (attacking), and 3 more to stay back in Diomande, Bah and 1 more.
Would probably cost 150m.
Now that totals 350m, but im quite certain with player outgoings in terms of transfer fee and them being on higher wages, we easily recoup another 50m.
We probably also need a new GK if Ederson leaves, but that should be more down the line.
Add in the youth players like Bobb coming back, McAtee, O Reilly and Wright as added depth, and the squad age plummets way down.