Cult: A singular leader or small group of leaders convince people who are looking for something to believe in/want to change the world of their worldview. The followers are willing to make non-optimal decisions in order to be a part of something greater/be close to the leader(s).
Warparties: A leader/small group of leaders convinces a group of people who are looking for something to believe in that they're on a holy mission: kill X. The followers are willing to make non-optimal decisions in order to be a part of something greater/be close to the leader(s).
Pirate Crew: A leader/small group of leaders convince a small group of people that they're special - and that they're going to work together to make a ton of cash. This is not necessarily true. The followers are willing to make non-optimal decisions in order to be a part of something greater/be close to the leader(s).