Clrnc i think the issue is that Arteta is buying players and thinking about positions differently from many people's fixed ideas of them. So what you see, particularly with players he has bought recently is a lot of malleability. Nobody knows what exactly Calafiori is, or Timber. Even Trossard. Havertz. He's more interested in sets of attributes that enable our way of playing versus fitting a traditional role in a 433 or 442 etc., as one might typically expect.
It also shows in how much formations and match-ups change within games, either during a transition or as game phases evolve.
A great example is Ben White. There are games where he has been a flying right back, inverted right back, and then right centre back; depending on what is required. And he does all of these roles well. You won't, for example, see Trent playing or Gusto playing all all these different roles in a single match.
