I think Wenger sees Campbell as a wide forward ala Theo or Alexis, Sanogo is seen as a Centre Forward, essentially Giroud's number two.

Wenger obviously sees something in Sanogo, I kind of do too but I would prefer if he was developed away from our first team, ideally at another PL Club. IMO The problem we face at the moment is that Sanogo hasn't really shown enough promise/potential to be viewed as an attractive loan for another PL club so we are stuck with developing him in our first team.

FWIW, I do think he will come good, he reminds me of Ade when he first came here.