I think the biggest mistake we have made is not giving him a Terry Phelan type figure as his assistant. I really feel a few of his mistakes as a manager could have been avoided with an experienced assistant with a couple of decades in the game.Hes one of the best coaches out there. As a manager he has a lot to learn. There's a big difference.
Ole for example doesn't coach United at all. He acts purely as a manager. He's been a manager for a very long time whereas last season was Arteta's first full season as a manager.
Itll take time for him to develop the managerial side of his game.
While I am not convinced by Arteta, mainly because of his style of football I am even less convinced by Stuivenberg and Round.