Special Forces Rise in a Primitive Tribe

Transmigrating to a Primitive Tribe, with a System: Rising from a Small Tribe to Unify Them All

Tribes, Farming, Development: Come Share Your Recommendations!!!

The protagonist transmigrates to a primitive tribe and starts developing it through farming, gradually bringing everyone under one rule. System stories need not apply. A golden finger is fine as long as it isn't too over-the-top.