German Wehrmacht sharing technologies with Italian troops
The best part of this to me is that a Roman legion would probably have been a much better ally than the WW2 Italian army.
A while ago, someone on Reddit wrote a long drawn out post about some marines getting sent to the Roman times and having to find their way back home. If my memory serves me right it started with a who would win scenario between a Roman legion or a squad of marines.
A movie studio contacted the guy who wrote it, and offered to get the right to make that into a movie from him.
The title is Rome Sweet Rome.