One aspect of the story that is glossed over here is that there were very few Vietnamese people in Dak Lak prior to 1975. The OP is a story of forced displacement against the Ede and Mnong people.
You brought up the people being displaced by settlements, but the film focuses on school teachers who get sent there against their will which completely changed the course of their lives. Back then almost everyone worked for the government and teachers, like soldiers, can be assigned to such outpost if they didn't have connections.