About Nam, the real think that Nam proved was that war can only be won if the political power i.e you,we,us want to make that war, and if I rebember well (I'm french so the political history of the USA isn't that clear to me)Nixon was elected on the promise that he would end the war. The second point that was proved by Nam,by Algeria, Rohdesia etc... is that you can't win a colonial war - well, you can if you exterminate the natives of course or if you park them in reserve - even if you win military on the ground as the USA won in Nam or the french in Algeria.
My wish for a CM3 would be Europe 39-40, then the french could win some engagement with their thanks B1, B1 bis ....after all we had the best tank in the world, but the worst high command leadership