Hmmm. You're in grave danger of believing propaganda films, Mr onetrack. Never very wise.
I think history has revealed that the NVA(or more properly the PAVN) were quite well equipped from elsewhere, and didn't generally have to resort to pulling Yankee toys apart to find ways of pursuing their aims.
However, their southern cousins in theViet cong (or NLF) had more reason to follow the suggestions you've outlined, being somewhat less well equipped than their northern brothers.
Not really fanatical or even particularly resourceful. Just getting rid of Johnny Foreigner who's cluttering up their back yard. Rather like the Afghans...