I know my hunter was dead orbit and switched to new monarchy because my warlock was new monarchy and switched to the rainbow coalition because my titan was in the rainbow coalition and switched to dead orbit. They care very little for the politics and beliefs of tower NPC's. To my guardians, these tower reps are good for very little other than to provide gear and the occasional quest like the crucible and vanguard NPC's. Since there are no restrictions my guardians are free to rotate out of a faction once it has run out of things to offer.