Well, the rules haved been written by many people, not just the owner of that site (if they were involved at all, this has been a NC driven event, that site owner is out of NY).
As to having four qualifying designs, note, three only vary by color. And the rules are VERY open as to requirements, they only have to weigh 3 gm, no other criteria except materials. No span limit, etc. And qualifying doesn't mean competitive. The min weight is 3 gm and these weigh 1/4 oz or more, about 7-8 gm. ALL flying events are strongly degraded by excess weight, don't expect those weights to be to be competitive!!