This is the section from release notes relating to your question. -2018-5-18tlopo-rc-v1.14.0
Guilds have a new rank: Co-Guildmaster!
Co-Guildmasters will have all of the permissions the Guildmaster has, except they cannot name a new GM or submit a guild name for review.
They will be able to kick Members, Veterans, and Officers.
They can promote anyone all the way from Member up to Officer. Only the GM can name Co-GMs.
There is no limit on the number of Co-GMs a guild can have, but it is recommended that the Guildmaster does not give out the position lightly.
If a Guildmaster names someone new as the head of the guild, they will now step down to the rank of Co-GM instead of Officer.
If a Guildmaster pirate is deleted, the game will automatically select one of the Co-GMs to be the new GM instead of an Officer. If there are no Co-GMs, the game will pick from the next highest possible rank, whether that be Officer, Veteran, or Member. ( hope this helps you out Leon.