This game and campaign for some reason evokes the video game 'Doomdark's Revenge'. That game features larger armies forming alliances and moving against one another. Would you ever consider adding a streamlined procedure for mass battles?
Outside of Flagrant Coasts I'm not planning anything - I suspect you could achieve something using Flagrant Coasts and having each 'model' represent more than a single model. Equally, there's a large number of ancients and dark ages historical rulesets which should work well too.
