While this film is dedicated to the idea that combat soldiers should be able to pick up and employ any foreign weapon in extremis, field results were uneven.
In June 1944, many Allied paratroopers picked up German weapons to supplement their own firepower or replace lost or damaged weapons.
This didn’t always work well.
In combat, all senses are at work, including hearing, and the very distinct sound of a German machine gun meant that the American that grabbed one found himself drawing American fire every time he lit up. There are quite a few such stories.