You seem to be way over thinking it, and way under-thinking it concurrently. Think of a kayaker, a runner, a snow skier. All the tracking device needs to report is the coordinates of the target. On board functionality can track this. The controller is at a stationary location providing overriding/adjusting inputs if necessary. This scenario is an additional level of sophistication for sure, but there is nothing in regards to the P3 design that would invalidate this sort of thing. Of the objections you state, the one issue which certainly holds validity is latency...and I suspect that is a difficult one to overcome. But as indicated at least one developer is working in it (we'll have to wait and see its degree of real world applicability), and certainly there are implementations where it makes sense to separate the follow target from the controller.