Shawn Marion was once also a candidate for defensive player of the year. You might want to dismiss perimeter shooting as a necessity and would gladly put Smith at the 3 but if this Rockets offense is going to be (or still is) built around Yao, you need perimeter shooting from your 3 spot. Josh Smith at the 4? I can certainly entertain that idea. At the 3? You're not only putting him out there to guard players he has no business guarding but you're also forcing him into a position to launch 3s he also has no business launching. And if you want to take your comparison further, both players function best playing the 4.
