The assembly of leaders consists of all Guild Leaders and votes about major decisions together, with the Governor making sure no fights between leaders break out or that decisions detriment one guild and favor another too much.
Not all guilds participate in every vote. Voting right in the matter being voted upon depends on the relevance to a specific guild.
Guild leaders discuss, debate and decide together with the governor in Leader’s Hall, which is on King’s Isle, kings isle also houses the governor’s mansion.