And by saying NOSE requires 16 teams, for each bracket, of course, I mean the game does. I'm not sure if there is a way to change that or not.
Now, if only 8 teams make the brackets, the easiest way to do this, with limited work on your part, is make all 8 teams face themselves in round 1. That way, you fill all 16 brackets. Then, round 2, is a true 8 team bracket.