TBH I think the bigger gaffe in Waterloo was using the tune modern German national anthem as the Prussian theme music... despite the fact that, in 1815, Deutschland Uber Alles hadn't been written yet, and the tune was only used for the Austrian anthem.
Thanks, I never knew that was the tune of the Austrian Anthem. Like the Star Spangled Banner being the tune of an old English drinking song. I understand why they used it, but your right it's historically inaccurate. Can you think of a tune that would be contemporary, and recognizable to a modern audience? I doubt modern audiences can distinguish between Germans, and Prussians.