Landry's value is higher, but oddly, I think Scola is a better complementary player with Yao and will help us more in the future. That's makes it a no-brainer: Landry.
They are both great but I agree that Scola could be a better fit with Yao. Plus getting rid of Landry will lower the cost of the Rocket's dental plan.
Scola's game does not rely on athleticism like a lot of players, it relies on his craftiness. Craftiness doesn't deteriorate as much with age (see: Steve Nash). Scola should still have the strength to hold up against bigger players, but also still have his array of crafty spin moves and scoop shots. I am not worried about Scola's age whatsoever.
but a power forward relies more on his athleticism and leaping ability especially for defending, rebounds, blocks, and scoring above the rim as compared to a pg who relies more on his iq and craftiness more than his athleticism and I would think Landry complements Yao better since Yao is crafty/high iq but unathletic