1. Making 10 categories is ridiculous, there's no way you will get that many people.
2. Why not just make one, no-level limit double battle competition, get 8 people to join and do it tree-style? It would certainly be more reasonable.
3. Why bother competing in the first place, since you know I'm going to win?
EDIT: Also, you really should make the battles have a 3-pokemon limit for single battles and a 4-pokemon limit for double battles. This is a standard rule even in the official Nintendo competitions.