If I remember correctly, the tested and non-tested streams are two different competitive streams. If you do a tested OPA show, you are then qualified to do the tested (national qualifier) provincials. If you want to do the non-tested provincials you would then have to do a regional qualifier (non-tested). there are usually about 4 shows to choose from within a couple months of the provincials each year. I think it is just the luck of the year and show that determine typical numbers. One year there could be 1-2, the next 5-6. I think missisauga is usually the bigger show - but even then you may end up lucking out and falling in a small class.

I hear you about placing by default. I often fall into a class with only a handful of competitors. It's usually the way it goes for the lighter classes I find.