So I gave it a try and have a few questions/observations.
If I right click on the clip and choose Pan and Zoom I get a different window than if I go into Editor and select Pan and Zoom. What's the difference? I chose to do the Editor version because it seemed to match your instructions better.
I got it to work "sort of". Doesn't quite work the way I wanted because I really need to track the two boys running down the field. The Pan and Zoom wound up losing the boys in the frame altogether at one point. That's probably where your "course correction" comments comes into play.
However, when I right click on the clip, in addition to the "Pan and Zoom" there is a "Motion Tracking" option. Have you ever used that? I'd like to do some research on that and see if that would do more of what I'm looking for. Perhaps I need to combine the two? Guess I need to do some more research.