Is not hard, they just have to occupy the center of the continent, and make any other outside region Rogue.
Is the only way to Unofficially, noncompetitive, dishonorable, disheartening, (CENSORED) way to win the game.
Which, OF COURSE, will bring a amazing Realm Wide Storm of Lighting Bolts, that even Thor, Pikachu, Nikola would be jealous.
I remember i had a discussion like that ion IRC around 2007-2008
Peace!
How would that bring lightning bolts? That hardly makes sense to me. If somehow you convince everyone to go along with that and not have Dukes seceding to form new realms or colonizations happen, I think you should be able to do it.