What are you talking about, City were just as fallable last year, after Elano lost form, and Petrov lost form they had nothing going forwards. Defensively they bought in the wrong players, they don't have a stronger squad, they have a couple better strikers, but they still lack wingers, they still lack right/left backs and Kompany doesn't really look up to being a top class DM, though with more support from left/right backs maybe he'll be great.
Hughes still has a predominantly Sven's side, they only really made one real transfer since the big money and that player has been outstanding. The frailties are the ones Sven brought in, remember they were solid defensively under Pearce and Sven made them a joke but brought goals to counter their crap defense. Hughes simply hasn't had a chance to get a defence in and is struggling witha bunch of crap players. I think he can do the job but this will be his first actual transfer window to make the team he wants in. Bridge might not be the best in the world, but looking at the rules that might be coming in you've seen that arsenal and City are making an effort to bring in English players, he's probably better than Ball anyway. City were far FAR better defensively with Richards at right back, not because he's poor in the middle but because the other centre back was decent and the alternate right backs have been beyond terrible. Its probably the way to go, bring in a world class centre back and push Richards wide again, Zabeleta is awful defensive and awful going forwards.
As for Arsenal the goal we conceded wasn't great, from a freekick, poor clearance by Diaby, not experienced defending from Gibbs let them cross it in and not great making the late run. Definately starting to click offensively though.