Night‑time cover is the oldest trick in the book, but it’s only as good as the execution. A fleet could throw a few ships onto a moonless horizon, use low‑profile sail arrangements, and let the smoke from a few controlled fires drift toward the enemy. If the attackers are still focused on the main column, the decoys can slip off with a few well‑timed rams or a sudden shift in wind. The key is to keep the false signal distinct—different sail positions or a different flag, if you’re that far back in history. It’s plausible, but only if the commanders had both the discipline to order a coordinated withdrawal and the chance to act on the confusion. So yes, realistic, but it would have taken careful planning and a bit of luck with the weather.