AH said as much after the Jan transfer window "I promised a stronger squad and I have delivered" including after crying on signing a "box to box" Liverpool player. He then admitted (unusually) sometime later that he'd got it wrong.
On the subject of Nolan - in my view he was lost without the influence of his mates, Alan Smith and Ameobi and Hardy had this vision about building around youth. There was no-one to lift Nolan out of the play-off gloom and we wouldn't have needed to be in the play-offs if the mid-season recruitment had been a better fit rather than upending the whole structure.