Policy should be going to try to sign the best players around 21-22 we can ones with huge potential like Lozano, Dolberg, Kluivert, maybe this lad Maddison, Tierney etc,
With the sum when they have s couple of seasons the sides improved due to them developing together, supplement that with players like Tosun, Carvalho, Coleman, Sigurdsson, who although older will still be at their peak when the younger ones develop. That way the entire squad sees that there is a long term plan that they will all benefit ultimately from commuting too.
Problem with having a group of young lads and veterans us that the 31-34 yo players know that even if it works they will be finished at that point.