Geoffrey,
From your comment, I would assume that you have not played Ballyneal. Also, I am not a member at Ballyneal, so I have no stake in the rankings. I think 6th in the U.S. is quite an accomplishment.
Ballyneal is not your typical course. In my opinion, it would take numerous trips around the course to determine the proper angle based on pin position, wind, etc. Yes, that is present at most courses, but even more so at Ballyneal. As for the other courses you mentioned, Sand Hills is the only one I've had the privilege of playing.