The MonsterInsider blog has details on a fan created tournament format for Monsterpocalypse called United States of Annihilation League.
From their website:
The attached document is a new resource from Terrence Miltner (ChiVenger), one of the Chicago Monsterpocalypse Press Gangers. Players should feel free to try out this league system that pits the six agendas of Monsterpocalypse against one another in a battle across the United States of America.
This particular league may not be a perfect fit for your gaming group, but it makes a great starting point for your own Monsterpocalypse league play. Feel free to change up the setting of the league, the required maps, or the cities’ agenda assignments to fit your own gaming group’s needs. Or change up the league format to a “slow grow” sort of league that starts out with smaller collections and builds up to bigger battles over time.