Documentaries on the WWII Pacific theater elide so much information they should be called Dummy guides by anyone familiar with events there. A Vietnam documentary would be no different, even if approached non-politically.
Ken Burns specializes in skipping what doesn’t fit his narrative. I wouldn’t accuse him of outright lying, but he selects what bolsters his leftist viewpoint and is not interested in material that refutes it.
I watched his Vietnam series and thought it was good. Are you saying the NVA were the bad guys? Now I feel deceived!