What would happen? Lots of invasions, lots of PvP, lots of people getting the 'disasters are gone messages', lots of gravelords getting action and either humanity, EoD, and souls, and the same number of GL signs... is this not what you want?
What should have happened is instead of having a war and two sides you should have just tried to recruit as many people as possible to gravelord. People would naturally fight them in any way, but I think most would try via the gravelord sign, especially if the GL sign was in the same spot to make it easy. Heck, you could switch locations every day just so we could maximize the number of forum members.
IMO I think the exclusivity is a cause for people to go against what you are trying to do.