Well, I guess that's a debatable point in the sense that we have Sambi but never use him (because some would argue he's not adequate squad depth).
Eddie also barely got game time in the league until Jesus was injured.
I guess my point is, your squad is as big/small as you want it to be (to an extent) so whilst I understand where you're coming from, I don't think it's entirely fair to say Arteta uses the squad to its full potential.