Possibility of these games?

[JDR Dragoon]

Well, there was a computer game made that sounds quite like what you want. Bit old though (1991):

http://www.mobygames.com/game/nam-1965-1975

The problem is, that what you are proposing will require some kind of political barometer (how fired up is the US/allied population? Is the government of the RVN willing to make the necessary social reforms that will effectively defuse the VC? How heavily will the communist block commit? How effectively can the givernments of Laos and Cambodia resist the delegitimizing effects of secret US bombings and later outright invasions? etc. etc.)

Another obvious problem is this: The game would be prohibitively long, even if you made the scale 1 turn = 1 day (which would make no sense in a game featuring tactical units as small as platoons).

No, I believe that if you want to do the Vietnam War(s) within the PzC/MC series, you have to stick to the mostly conventional phases. That means roughly the Dien Bien Phu campaign (1954, siege lasts 57 days = 57x7 = about 400 turns), the 1972 Easter Offensive (200 days, various phases from late march-late october, 200x7 = 1400 turns) or the final 1975 offensive (mid december to late april, about 140 days or 980 turns). You could of course cut down on the number of turns or just do sub campaigns (like say the battle for Kontum in 1972).