I always thought it was funny that for the final push into Saigon in 1975 some in the Vietnamese hierarchy wanted the drive to be spearheaded by reconstituted Viet Cong* units. The North Vietnamese Army basically told them screw that. We won you lost.
*After devastating loses at Khe Sahn and the Tet Offensive, the VC ceased to be an effective fighting force and it’s few remaining troops we absorbed into the NVA.
The Viet Cong were toast after the Tet Offensive. Walter Cronkite turned it into a huge win for the North.