Yup, correct explanation.
There are two primary types of racing in the west, long single loop events commonly called Hare & Hound, and short course mulit loop events commonly called Hare Scrambles. In a normal Hare & Hound, the course is comprised of 80-100 miles of trail, and generally covers one long loop or two separate loops with a pit in the middle. Point to point events also fall into this general category.
In contrast, a Hare Scrambles is a run over a short course, maybe 8-10 miles, and raced for a predetermined time. The rider who completes the most laps wins. An example of a Hare Scrambles format is the WORCS series, but an MX track is thrown into the mix of WORCS conpetition.
Along with the Hare & Hound events, the ISDE Qualifiers are another example of a long one loop event, but these have timed checks in the event, as well as special test sections. However, the format is still more like the Hare & Hound events. Unfortunately, since the ISDE team has little to do with competing in the Qualifiers anymore, they are on the decline.
Also, because of land restrictions, long one or two loop events like the Hare & Hound are also on the decline. Another nail in the coffin is the lack of spectator friendliness. Since sponsorship money follows spectator involvement, the more condensed events like the WORCS series have become the place to make the best money. This is exactly why Ben and I have moved away from the National Hare & Hound series, and into the world of WORCS racing. Better sponsorship support.
As for overheating, a properly jetted 500 will run wonderful in any terrain any time of year. Remember, the National Hare & Hound series events are run in the desert, with race time temps at or over 100 degrees. Since every HH event has tight technical sections, if the 500 were prone to overheating, it would not be the front runner more consisitently than any other machine.
Rick