fun fact, the whole Montagnard actually happened. The BAHARAKA (named after the 4 main ethnic groups in the area), later the United Front for the Liberation of Oppressed Races (FULRO - named after the French name), was an organization set up to demand autonomy (or even separation) for those ethnic groups as well as the other smaller ones. Both the South and later North Vietnam government opposed to the autonomy demand, so they started to fight both. The organization's activities carried out even after 1975, until their last members were apprehended in 1992.
Because of this, the current Vietnamese government got really cautious against ethnic groups. The general consensus is peaceful negotiation, but respecting the difference in tradition and culture while trying to develop the area enough to provide everyone basic education, healthcare and and other public service proved to be very difficult.