I am not sure I understand correctly. If you’re talking about the chumchon (community). It is exactly an urban subdivision, not standalone. A sub-part of a larger settlement (town or city), not an independent one.
For place=village / hamlet, I still prefer the administrative role to determine whether it is, because the criteria is clear. The official village status requires 200 residents (or used to have 200 residents). The isolated settlement with a lower population would be officially recognized as part of another village. Thus, if that unofficial village have a name that people call, we can tag them as place=hamlet. As far as I know, there wouldn’t be many of them. Most villages you can see on the sign would be place=village.