So important to remember that Napoleon III was a despot who subverted his republic, and replaced competent people with blind loyalists. The result was a mismatched war, and soldiers like those sharpshooters put in impossible situations.

Yasss, check out Émile Zola's "The Downfall", a novel about the Franco-Prussian War including the Battle of Sedan, there's a copy on Project Gutenberg, iirc it includes a description of this action.