If the movie was good, I honestly wouldn’t mind at all. Sure the realism/immersion is broken, but not all movies are striving for, or even care about that. Sometimes breaking the immersion is a cinematic choice in itself. With the case of The Last Duel, the purpose was not to paint a realistic portrait of France during the 1300s; the purpose was to tell a more universal, Rashomon styled story that resonated with the “me too” movement that was happening at the time.