California Doubling: Double subverted. The film is set in the Ia Drang Valley in Vietnam, but was shot in northern California, which in turn is a dead ringer for the Ia Drang Valley. Not all of Vietnam was jungle or city.
Follow the Leader: Was one of the war films following up the giant success of Saving Private Ryan that displayed realistic combat violence but was also respectful to the cause and sacrifices of the troops involved. Really worthy of note given how most of the iconic films about the Vietnam War released prior portrayed things.