1 CB (first XI)
1 RWB (first XI) I'm not convinced by spence
1 CF (back-up) better if he can play also in the son's position = depay? morata? bergwjin?
to change to much is a big risk, we could lose identity and can lead to dressing-room problems
In some cases, yes. Imo though this is more when there is too much change in the form of players who - almost - automically slots into the first 11.
Our top players - Kane, Son, Hugo, and arguably 1 or 2 more - will want to start competing at the top end of the table and have a real shot at a cup. They'll know that squad depth absolutely needs to be adressed, also broader than your suggestion. As will everyone in our squad.
The only player we've signed so far who automatically slots into our starting line-up is Perisic, and you could make the argument that he'll be the only one, no matter what happens. Bissouma will need to take a spot from Skipp, PEH, Bentacur. Whichever one or even two attacking will need to duke it out with Kulu for starts plus rotation starts. Even if we sign a top class CB then Dier and Davies has earned that it's their spot to lose.
I'm completely convinced that the whole squad understands this. Those who didn't have already been put to one side. If Davies, just to single out the most vulnerable starter from last season, wants glory, he'll have to be good enough to see off competition for his spot from top level signings, and of course he respects this fact. Otherwise Conte wouldn't have started him every match.
Even 5-6 more signings will not be an issue imho.