OK. So they've lost a striker who produced 53% of their total goals last seasons, plus (it seems) a player - Song - who was basically the mainstay of their CM last season.
In return, so far they've signed the very talented Cazorla, plus Podolski and Giroud ... all three of which may take some time to adjust, as may the Arsenal team as a whole given the loss of two such influential players.
Of course they have Wilshere to come back ... but when exactly, and how much of a 'hit' his performances may take from his injury, is still very much open to question.
Their defence last season was very leaky (conceded only 3 less goals than WBA). It may improve this time around, but by how much?
You have to think that the continuing player exodus will have an effect on squad morale and cohesion, with many players thinking "who'll be next to jump ship?"
All in all, I'm not convinced so far that Arsenal will be better than last season ... and they may be significantly worse.