I'll try to make sense here.
I think we'll get used to the squad being thinner than usual. In Bologna, Motta has 28 players, but he only plays around with 17-18 players. I add a pic below. You can see that out of 38 matches, 17-18 players played most of it.
https://1xbet.whoscored.com/Teams/71/Show/Italy-Bologna
Now Juventus is different from Bologna. This season, we'll have 50+ matches to play, with little time between matches. So what is in Motta's mind? In his first press conf, he said we'd have a squad with 23-24 starters.
https://football-italia.net/every-word-thiago-motta-first-juventus-presser/
So, assuming that he didn't lie, then we'll need only 4 more signings to complete the squad. 1 AMC, 1 RW, 1 CD, 1 start/sub LW. Hopefully next week we will close the first two with Koop and Nico. The other two can wait when we try to offload some more.
I don't comment on whether this approach is good or not. Just try to guess the situation. I remember Jose Mourinho said that, for him, a 23-players squad is optimize, but never seen a club really build like that.