You can have one player like that. It obviously does help to have both. Even if Arteta had eyes on the back of his head and was aware of everything going around him, it still helps to cover ground quickly. But since Diaby and Cazorla are pretty quick, we can close gaps pretty quickly as long as Arteta can effectively play the role of conductor or can just cover for others well. The whole 'Makelele is underrated' type attitude is a bit played out but in Arteta's case, I think it really is a thankless job. If he was English, he'd be the best midfielder in the England squad right now, but he doesn't quite get the respect he deserves from the media. He probably got more praise at Everton. Still, at least the gooners rate him.