i think you mean are you controlling *the* tracks with Parent track motion.
If not then you will have to move each one equally where as if you use parent track motion, you will be able to move all tracks together once you've placed them using the individual tracks track motion.
This is also how you can do large 3D Planar grouping in Vegas as well, (as long as you convert all compositing modes to 3D source alpha)
Remember, also, that the parent motion control is along the far left edge of the parent track; using the parent track's individual track motion control will not control the child tracks.
That would be using many tracks as a group to create a 3D object.
For example, you could use six tracks and make a cube out of them, then rotate that cube around in 3D space using parent motion. As long as you have the positioning math right, it should be seamless.