California Doubling: Double subverted. The film is set in the Ia Drang Valley in Vietnam, but was shot at Fort Hunter-Liggett, an Army post in San Luis Obispo County, 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.
In Real Life, the battle at LZ X-Ray was largely a draw, with both sides achieving the goals they set out for: The Americans wanted to seek out the North Vietnamese Army in a large-scale engagement and force them off of a base they had established, as well as testing out the new Air Cavalry doctrine the US had developed. The North Vietnamese wanted to lure the Americans into a prepared ambush and similarly probe the new enemy to figure out their strengths and weaknesses. Ultimately, the surrounded and outnumbered Americans persevered because the NVA was unable to cut off their air bridge: the helicopters kept bringing in fresh supplies and reinforcements, and carried off the wounded, while repeated air strikes kept the NVA from being able to overrun the landing areas. Ultimately, two more American battalions were flown in, evening the numbers out, the NVA withdrew, and the Americans similarly departed soon after, to clear out of the area before a carpet bombing strike of the area by heavy bombers. In the end, the battle ended with neither side holding the territory in the immediate aftermath.