I don't get why so many football fans seem to think that playing in the middle as a striker is some kind of reward, and if you don't cut it, then you have to play on the wings. I mean I know that there have been players who began their careers on the wing and then later played as CF or striker, but that doesn't mean it should always be like this. Giroud is just not a winger, and if you field him and Walcott, then Giroud should play as a striker and Theo should play on the wing.
If you want Theo to play in the middle up front, fine, but then leave Giroud on the bench and let Arshavin play on the right wing or move Santi there and go with Arshavin or Wilshere as CAM (with Arteta and Coquelin as DM).