We agree on We Were Soldiers but as far as showing as history, Full Metal Jacket did not impress me much as a Nam war film. It had a more WW2 feel to it and I chalk this up to Kubrick being a hermit for the past 20 plus years before the film was made.
I like The Boys in Company C but there is one question that drove me nuts. The 'boys' had finished basic and one asked, "What's an 0300?" I almost barfed in the theater!
Tell those high school teachers to show Go Tell the Spartans(1978) for it is much more factural about the Vietnam War, especially the early years...