Viets are showing off their new toys,lol
And they were able to bleed the PLA dry during the Sino-Vietnamese War in 1979. Even their paramilitary units had easy pickings on the so called 'crack' PLA units.
Don't underestimate the Vietnamese. They have a history of humbling great powers: Khmer Empire, Champa Kingdom,China, Mongol-ruled China, France, the United States.
In fact I find great similarity between the Vietnamese and my people in Japan. Both Vietnam and Japan were able to successfully repel Mongol invasions , whereas the Chinese were incapable of do so. China was conquered by the barbarian Mongols and later the Jurchen-Manchu tribes.