Asik is good, but I wouldn't pay him 8M this season and 14M the next when we need minutes to develop our young players. Houston would also want a young player to do this, and I don't think that makes sense.
Morey probably doesn't want to pay him the backloaded year of his contract to backup Howard, so he's probably trying to unload him.
Who would probably want to pay him? a team in need of a defensive center to contend. I think OKC is the perfect destination, hence the 3-way trade proposal
here.
This way, Houston gives you a future asset, and OKC gives you 2 assets for eating Perk's contract.
If you trade straight for Asik you have to give assets, and HOU is not taking Wallace unless you give multiple first round picks. If you're trading Humphries for Asik, you're losing your cap flexibility around next Draft. Doesn't make sense, in my opinion.