The worry I have with Arsenal's technical setup is pretty much totally based on the Pepe/Zaha affair. We know that Raul and Edu will move players (in or out) even if Arteta isn't on board. When Arteta says he wants people to stay, I believe him, but generally all coaches want their players to stay and then they want more. It's a natural kind of desire. That's why technical directors need to be able to make those medium-term decisions that take resources into consideration.
Thing is, Arsenal has proven that it is willing to leave the team short. It's become a norm. I think it started with Wenger, who seemed to like "reinventing" players and coming up with creative solutions. Arteta strikes me as someone who wants 3 players in every position, and then some. Similar to Pep in that sense, I guess. He's got to be careful that he doesn't fall into the trap of "well, you got another backup winger so you can't ask for a backup striker, too" kind of relationship with higher-ups, because they'll cut him off at some point. He's got to pick his battles.
