Not at all. This is a piece of mythology repeated by people with different political agendas that downplays the complexity and organizational sophistication of the National Liberation Front's Main Force units (the Viet Cong). The original wave of Main Force VC that entered South Vietnam starting in 1964-65 had limited weaponry, that is true, but they were an overall well trained and effective fighting force. They were also politically motivated, as a large portion of this wave of insurgents came down from the North, tended to be ideologically Communists, and supplanted the mixed coalition of the NLF that had existed in the early 60s. It's also important to note as well that the Vietnamese had a seasoned pool of manpower that had fought the Japanese and the French.

Colonel David Hackworth's memoirs do point out an important distinction within the Vietnamese insurgency however. There were (his words) "local G's" that had little to no training. US documents also distinguish these types of insurgents from the Main Force units who were the real threat. Main Force VC were trained in ambushes and other guerrilla tactics and as their supply lines through Laos and Cambodia their access to better small arms and explosives improved. The VC developed a tactical doctrine of "grab their belts to fight them" which meant basically close-up ambushes and attacks on American forces in order to neutralize the close air support and artillery usage. This is on top of the North Vietnamese Army that also took part in the war against US and allied troops with great effect.

The Viet Cong also had a well-developed political mobilization element that worked in tandem with the military units to control villages in the South and use them as sources of supplies and recruitment. This was just as important to their war against the Saigon government and the US as their military actions.

The short answer is that no, the Vietnamese insurgency and North Vietnamese army were not plucky farmers that took on the United States and won. The romantic image of the guerrilla as someone like this may be comforting to some or endorse their particular political rhetoric, but the reality of the Vietnam War was a confrontation between two professional armies, only that one employed guerrilla style tactics as a way to remove American advantages.

You can also take a look at:

Col. David Hackworth, Steel My Soldiers' Hearts: The Hopeless to Hardcore Transformation of U.S. Army, 4th Battalion, 39th Infantry, Vietnam

Truong Nhu Tan, A Vietcong Memoir: An Inside Account of the Vietnam War and Its Aftermath (One of my favorite memoirs related to the Vietnam War)

Warren K. Wilkins, Grab Their Belts to Fight Them: The Viet Cong's Big-Unit War Against the U.S., 1965-1966

Martin G. Clemis, The Control War: The Struggle for South Vietnam, 1968–1975