The Red Badge of Courage (1951)
At the end, when the troops are marching, you can see shot of the sun as similar as seen in Rashomon
Lobby card shown
Z's witnessing the aftermath of battle matches Henry Felming's.
Mentioned by Richard Curtis when he says the title 'The Black Adder' was inspired by old Hollywood film titles featuring colours like black or red.
"It's like the red badge of idiocy."
Footage of this movie is shown.
similar title/plot about reenactment of Civil War