You're right, it scales the skeleton up or down. Like for Yoda, the scale is .34, or a third of the natural skeleton size. However, I'm not sure if the model itself is affected by this...
I'm pretty sure that says "scale the default skeleton up to this amount" -- why do I say that? Becuase any model that uses custom animations only uses a few custom anims. So, let's say Vader's skeleton is 1.25x bigger than a normal unit's. Adding SkeletonRootScale = "1.25" scales the root skeleton to the same size as Vader's so he can use all the standard anims.
For combos, yeah. It *should* be okay with standard animations. That is--- if you're not using combos, you should be able to scale a regular trooper up or down.
I tried with both a regular trooper and vader. For the regular trooper, nothing happened. For vader, I took out his lightsaber and he shrunk to normal trooper size...
Any idea how I could fix this or why it happens?