Didn't see the show but had to comment on the brethren thing.
My father was born and raised Hutterite but left the colony when he was about 20. He maintained family ties and is not shunned. I spent a fair bit of time there as a kid and looking back, the similarities between them and the dub mindset and social engineering are apparent. Both are isolationist religion based communities that limit outside association and exposure to information. A very patriarchical community with clearly defined roles and responsibilities and a strong basis in their interpretation of the bible. Traditionally humble in attire and attitude, they pretty much keep to themselves and don't integrate. This and the fact of their communist approach to possessions and lifestyle is closer to Amish than Mennonite I would presume. Mennonites seem to have integrated more readily. The movie "The Village" reminded me of the dub connection obviously but also the Hutterite approach to it, a sort of mix of both those worlds.
I have know a few other Hutterite "runaways" who've left and made a life "outside". I have no doubts that they go through much the same as xdubs albeit as escapees of a somewhat less judgemental but no less unsupportive subsection of society. They are known to have their "apostafests" from time to time,...