I think you guys are way too optimistic with the minute allocations. It happened to work last season with Bastoni, that he didn't have a usable backup but will it work next season too? Are we going to bank on that?
Pirola has played Serie B (won a starting spot there after half a season so at least there's that), so it would be quite a something to jump from there to Inter, the title-holders.
Cut out D'Ambrosio (who we just extended) and Ranocchia, to be replaced by Gravillon the Ligue 1 shitter? Zappa? Come on. Who's going to back up any of our defenders in this scenario? Dimarco alone?
Midfield thing I can give you that we can dump out two midfielders and be basically the same as last season, almost. But then again, our problem is still the depth (and was last season too). If we let Vidal and Vecino go, fine we stay with Barella+Brozo+Eriksen+Gagliardini+Sensi and then bring back Agoume perhaps? That's worse depth than last season.
I simply don't feel this over-optimistic narrative here with the cost-cutting.
The renewals and thus payraises will mitigate any big salaries going out. Then if we replace outgoing players with shitters, then sure, we will end up saving salaries but our squad is not going to be better, or maybe even at the same level as last season.