From the wiki: "The town's social cohesion stems in part from its many large extended families. Most residents are native to the area, and it is customary to marry within the town."
Further, Cheran is a small area, they had a very clear reason to do this (and they were "all" in on it it seems), they are still in the "let's try to make this work" phase and so on.
This, certainly.
The effort to do this appears to be unprecedented,
and that may be their page in the history books.
