I never thought Chamakh was a failure, I seem to remember that he was doing OK and scoring till RVP came back from injury and he was completely dropped by Wenger, never gave him a chance since. I think the Podolski signing is much more likely to turn into a total waste of money for Arsenal. He only plays well when surrounded by the likes of Ozil, Sweinstiger, Klose...etc. At Koln, he's average at best. Giroud, on the other hand, I think will prove to be an important signing for the gunners, though they will still be a weakened side without RVP.