Does GBG Use an ELO Rating Scheme

Although only on the 4th GBG, one pattern that seems to emerge is that the GBG following a 1st place finish is always brutal and much more competitive (within the same League).
Is there any information on whether Inno is using an ELO-type rating scheme to stratify the guilds so that a win will take you upward in the Guild League rankings and pit you against similarly ranked teams rather than just a random pairing within each League?
So far, win--struggle for 4th/5th--win--struggle for 4th/5th.
Is there any information on whether Inno is using an ELO-type rating scheme to stratify the guilds so that a win will take you upward in the Guild League rankings and pit you against similarly ranked teams rather than just a random pairing within each League?
So far, win--struggle for 4th/5th--win--struggle for 4th/5th.