The gangs were able to choose from 2 options.
Option 1. You have stayed in whatever limited contact with your house or a house representative outside the Sumphulk walls.. (can be creative here.. via whatever means.. vox, rat delivery messages, passing code, tapping on pipes ) you’re a true (insert house name) until you die! You are carrying on the traditions of the house in the sump hulk.. you make a living here... Your first generation had a mission here that’s been almost long forgotten now. You still cling to hope that maybe one day your house will come rescue you from the hulk.. maybe one day.
OR
Option 2. f**k your house, you do what you want now. They abandoned you anyway right? You may carry on some of your traditions but you report to no superior. You are the superior! You have accepted life in the dome, and are carving out your own traditions and you got no idea why your stupid ass ancestors got stuck down here.
Goliath 2
Escher 2
Delaque 1
Cawdor 1
Van Saar 1
What they know about your gangs possible origins in the dome:
Cawdor: Stories have been passed down from your gang elders about the great cleansing crusade to return the stolen tributes. There was a also some talk of a splinter faction of brothers that worshipped a false prophet who preached about the "Pale Emperor" waaaaaay back in the domes early days.
Delaque: The whispers from the house are that the founding gang were on a mission to defend the House's stranglehold on the rulers of the planet. Knowledge is power and their whole network was under threat. It was a mission of utmost importance and that they had succeeded.
Van Saar: Its been passed down that your brothers in arms had 2 missions. The first was in search for a particular specimen that was imperative to the future of all van saar. The outcome of this was unknown. The second missions data log has been long lost but a lone surviving preserved image shows the original team celebrating a victory.
Escher and Goliath: You have no idea.. at some point your gang splintered and cut ties from the house. You don't lose sleep over it and both have carved empires of trade and a fearsome reputation in the Sumphulk. You hate each other and couldn't stand the thought of each other gaining more power or influence over the Hulk.