Interesting if that is true, and they are using a different algorithm that exactly matches the algorithm that some players have figured out.But yesterday Forge said on FB "There are a range of factors involved in pairing guilds for GBG. Guild ID is not one of them. In the higher levels, there is less chance of it being mixed because there is a small pool of guilds in that level. It has nothing to do with guild creation date. "
Maybe it's just a FB mod that doesn't know any better.