I think you're right, there is a major jump from being 80% self-sufficient to 100%, and Cambodians have been living somewhat off-the-grid for centuries. There are some things that are just more efficient for a specialist to do.
In Cambodia there's always a cobbler in every village, but there's no need for more than two or three, because that is a dedicated skill that takes a long time to perfect. Rice growing is another example too, that is such a dedicated job that it's hard to do much else other than grow rice.
Cambodians without money will often hire villagers with less or no land help with the rice field in exchange for x number of kilos of unhulled rice, for which they winnow, dry, and mill themselves. I think ***@fenngen is on a good path, and community can only make things that little bit easier.
!ENGAGE 45