If Allegri plays Pogba as AM in a diamond or 4231, Rabiot will play with him. But I noticed Rabiot never plays RCM, seems confused there without being able to go wide with his left. And Pogba is a LCM that likes hugging left to drive and create.
So if Allegri sticks to the 433 to give Pogba his favourite left side, I forsee Rabiot more on bench. McKennie, Zakaria will play more right side. Maybe Fagioli too like in this game.
Preferred foot and style matters alot. For example McKennie is right footed like Pogba but he can't play left CM, all his worst games has been when he has been forced left, instead of right or central. Just how certain players like to play, habits and best way to get the best out of them.
It depends on the player. Rabiot many times stated that his proffered position is LCM and he doesn't like to be played deeper. Pogba proffered position is the same. It right though that they are different players, Rabiot is more defensive while Pogba is playing almost like CAM.
Now to the Zakaria and McKennie, both can only play on the right because they are limited when it comes to weak foot, Zakaria even more as he is actually never using his left foot.
Fagioli I don't know, looks like more technical player so probably could adapt to both sides but we are yet to see this. So basically what we have now:
LCM: Pogba, Rabiot and maybe Fagioli
CDM: Locatelli, Arthur, Rovella
RCM: Zakaria, McKennie, Fagioli, Miretti
What I would like to have:
LCM: Pogba, Fagioli
CDM: Locatelli, Rovella
RCM: Zakaria, Fagioli, Miretti
I'm yet to see but my understanding is that Miretti could also play both sides same as Fagioli. The one possible change is Paredes instead of Rovella and it really makes some sense, Rovella might be not rated by Allegri, we hear nothing on him from Max. In this case it's also possible to move Locatelli to RCM or LCM when both are playing.