I wouldn't even bother considering concealment as an issue.

I doubt that joining a group would have to be a permanent situation. Find out what you can from observation, if anyone else knows about them, and then quietly approach. Interact, and if it isn't workable, walk away. If you have food or goods, leave them stashed in a safe place. Don't trust too soon, don't run off at the mouth, don't drink, don't go after the girls or women. IOW, don't be stupid, as your life may depend on it.

It makes me nervous, too.

The only hopeful thing is that people who think alike might flock together. The ones who won't contribute may be asked to leave. The blustering self-proclaimed leaders, likewise. But that would only happen if you had a group of reasonably sturdy personalities who would stand together

They used to be called 'communes' (not just the 60s, but even eons ago), and were probably the only examples of a true classless, stateless society that have ever existed. But how long it would last is anyone's guess. There are always the people who want to control.

It's tricky at the very best.

Sue