I used to be high on Gordon.
After reading someone basically call him a Jeff Green except undersized at the 2 (to paraphrase, they said "Gordon's useless unless he's scoring"), I'm not so sure. I'm under the impression he's a better shot creator than Green with the ability to handle the rock but his numbers suggest similar inefficiencies (presumably because of his lack of size he can't get to the rim as easy).
I'd probably still do Gerald Wallace for Gordon though. But for the same reason I'd do Gerald Wallace for Josh Smith. The Wallace contract is going to eat up space anyway, might as well get something that's more moveable despite a worse contract.