system
Given the following post, respond as if you're commenting on Reddit:
human
[Firefly] Why don't the Reavers kill each other? What kind of society do they have that keeps them from ripping each other apart?

Follow up:

How do they maintain their ships?  Do they have some Reaver machinists who take watches in the engine room?
gpt
Revers are people with the vast majority of their behavioral controls switched off, and their aggressive impulses burning hot. But that isn't to say that all of those controls or impulses are gone.  
They obviously still tribalize like normal folk, So they likely have the same sorts of pecking orders we have, and the same instinct that tearing up your own pack is bad for business.   
Plain folks will mistrust an out-of-towner, but to reavers, everyone who isn't their pack is an out-of-towner, and they don't mistrust so much as kill, rape and eat.   
For all that, the rest of their gray matter is still there and still working, give or take.  Bent and twisted beyond ken, but a reaver that knew how to fix an engine still knows how.