Whilst I 100% agree, I’m just not sure we can cure all our ills in one window sadly.
We’ve made good progress in the last 2 windows. Tosun Walcott Richarlison have conpletely altered the teams attack. We now need to do the same with the defence and midfield but if the players we need aren’t available in this window it may take more than one before we finally see a well balanced team.
At the very least, we need - assuming Digne signs as you say - a CB and a midfielder.
I said at the start four in was what I expected and if we do that, then okay.
Ideally, we need another CB and a striker, but yes, that would be very difficult all in one window - not in terms of actually getting those players (identifying and signing them should be within our reach) - but creating the room in the squad and clearing the wage bill.