Just an Idea to keep the game interesting. When my friends and I played the board game at the end of the campaign the winning gang was 'Promoted' by their house. For the video game it could be a cut scene where the played accepts of declines their house's offer to move up the spire. At which point either all or part of the gang would be 'retired'. If part then the player would have to recruit new fighters and continue, should they accept. Should the decline then the gang stays com-plete and the player can keep fighting as if nothing happened.
It's mostly cosmetic I know but it gives people an end goal besides the story mode ending. I think most people would like to know that there is an ending or a target to reach.

I like the general idea that you could retire gang members or the entire gang at some point, then be told what happened to them based on stats, skills and other factors.

For example - joined the PDF or Imperial Guard, got recruited as a Space Marine, Sister of Battle, Mechanicus Priest, Assassin, etc. Or became a noble, a Spyer, or fell on bad times and got reduced to a Scavvy, Servitor or even Servo Skull, lol.