I think you need a squad of 22 players, two full teams to cope with all the games that make up a season & all the cup games, if you are a top six club that wants to win silverware.

so at least two midfielders, cb, two right wingers (chiesa leaving) needed this summer then

Yes, that is right, plus replacements for M.S. A.R. & I.K. But the big signing we missed out on was Alonso as manager.