Hi Paul, that is how I read it as well.
That said, I'm not buying it! When I did the tetons earlier this year (
link), you specify your group size up top and it has number of people available grid (sites by dates) where you can pick and then add to cart. Key here is, replace people with sites, and it all works. Website would show a grid of campground by dates, with quantify available, and group site size (1 or 2) being able to be specified.
That said, I agree with your concern with the 2 site limit getting first run. That certainly opens up an easy way to cheat the system, especially if people aren't aware of the changes and don't realize they need to apply on March 1 for groups of 5-8.
All that said, 'this is the way' : yellowstone (
link)
They say it better than I can (emphasis mine):
Because demand for backcountry campsites in many areas of the park exceeds capacity during peak periods, an optional early access lottery is available. This lottery is based on a fair and randomized process to provide an equal opportunity for each applicant to be selected. Successful applicants are granted early access to reservations, with the earliest access having more options to secure a reservation for popular areas. Lottery participants with later access may not have access to their preferred itinerary but can create an alternate trip using available campsites.