[jstanley]

I think the point is that in order to follow it, you need to (at some point in time) be at the same place and with the same velocity. Then you'll follow it.

But the energy required to do that is almost the same as what it would be if the dwarf planet wasn't there. You could get onto exactly the same orbit for roughly the same amount of energy, and if you relax the requirement that there be a dwarf planet nearby, you can choose superior orbits.