Unless things have changed recently, the object of a defence is to prevent goals being scored: pure and simple. Thus, in only 2 of 9 seasons did the much vaunted George Graham defence beat the leaky and hopeless Arsene Wenger defence of the past 6 seasons.
I am not trying to make Wenger out to be some genius when it comes to creating or organising defences. I am trying to stop people making the George Graham defence out to be better than it was.