One of the issues with Arteta is it looks like for whatever reason he may have 'fallings out' with certain players, not necessarily a big beef but basically decides he doesn't fancy X and then that's it, they are done.
Ozil was in the team before lockdown1, sort of a redemption following the end of Emery's rein, and then completely cast aside for project restart.
Torreira is out of favour, despite being our best holding midfielder.
Auba/Laca, you never quite know what to believe with all these rumours about Barca, but regardless he doesn't seem to get the best out of them. I don't see how Barca could afford Auba anyway, he's not going to take a pay cut.