Four guilds with four leaders. It would be fun if they were oriented to some point that does not define them as good and evil, but like this: one is arcane, second spiritual, third might and fourth is technological. They are all using swords, but might have these really big ones :) Arcane imbued with magic, spiritual blessed ones and technical. Well... really sharp ones? :) They all have magic, but mighty one have animal spirits and earth bending magic, like earthquakes, Arcane ones a lot of sparkly one and technical could use wand with gear ;) siege machinery? All have them, but mighty ones are REALLY BIG, technological have a lot of gear on it, and arcane are powered by crystals, for example
The point is that each member can build in direction that he likes, end then decide will he bring peace to the land, or his own ruling, if he can conquer it :) and, member can also choose if he will build wizards or warriors, just flare it up a little with its guilds properties. And, like someone sad, I am one step away for contacting lego to build me a flag from trans neon green, pair it up with red, arm to the teeth and start conquering the land - Dark elves need a lot of slaves, you know :)
Each member could have a guild sigfig, and incorporate it in his (hers:)) mocs. Each member could, if he (she) likes think up a story of his sigfig history, and post it, it could be interesting. Each member could start as a footmen (or peasant or apprentice) and work his way up with mocs (and/or points), and earn his lordmanship :) If we are all playing good, we could take care of each other, not to get carried away, and this whole game can stay a game :)
I like idea with points and competition, and each guild should have its own color, and part of the map that has been ruled by it should have (90%) opaque layer of that color - and if other guild expands, its color takes over. VERY opaque layer of color, barely visible, but visible
And at one point, if this goes to life, fifth guild should emerge, cold, icy and dark, but more about it later ;)
Each guild could organize one challenge or competition in some time interval, with its own members rules and prizes, and members of the guilds could have duels, with limited time building, or usage of the part, or something else (highest 32x32 tower or bluest soldier in the army:))
If sigfigs are generic enough we could make them and make visitations to our castles, stories and other fun stuff