If your 17 are all high level players and not players like Janssen, Llorente, Nkoudo, Foyth( not his ability his experience) Sissoko then it makes little difference if you have 8 or 4.According to a not always reliable source elsewhere City had 18 senior players last season, only 4 home grown (Sterling, Delph, Walker & Stones).
I don't know if that's true or not, I do know it's a matter that's barely mentioned for all other clubs apart from us. I suspect it's this year's excuse, little more