I'm not sure wtf Arsene is thinking.
I didn't see the game today, but here's my guess. We've struggled mightily to create goals through the middle of the field since Cesc left. Wenger has reverted to a style of play that was similar to our early noughties teams, which means we get the ball wide to the wingers, who pump in low crosses to players in the box. The problem with this is two-fold. In our system, there is only ever one striker in the box at a given time. Secondly, our problem is that we move the ball far to slowly. Literally every player we have save for Arteta and Cazorla is slow in moving possession, and rather slow in receiving it. We can't outskill teams, so we try to outrun them, but we don't have the requisite technique to take advantage of our athleticism. Arteta and Cazorla link well because they understand the field holistically. Most of our other players don't.