I just realised there's a 5th character we never see or hear about: the camera person. In the first 5 episodes, the camera is operated by someone we never see. Perhaps there are multiple operators, recruits who come and go like we've seen before, however I think there's evidence this shows this isn't the case.

In episode 5 "Cleanliness II", the camera operator seems to be beyond Curtis's suspicion. This leads me to believe this person may be Curtis's offsider, the cofounder of cult or perhaps even the founder. We're never explicitly told that Curtis is the leader, he may be high ranking or second in charge and delegated the tasks we see.