I'm not too surprised by this. I don't recall if I've ever read a history about Kriegsspiel (thanks for sharing it Paul), but it's chock full for Napoleonic names.
https://kriegsspielorg.wordpress.com/ho ... riegsspiel Beyond the obvious of Friedrich Wilhelm III & his sons Friedrich and Wilhelm, the fact that Karl von Müffling took to it is really interesting to note, especially given his presence at Waterloo. The mention of the Prince von Mecklenburg taking the other side in game was probably the King's brother-in-law Carl zu Mecklenburg. Also, August Friedrich Ludwig Karl von Reiche, who was the Captain of Cadets that mentioned Reisswitz to the Prince's Governor and taught them as well as their cousin Friedrich Wilhelm Ludwig. Von Reiche had considerable Napoleonic experience and his cousin Ludwig von Reiche formed & led a Freikorps, the Ausländisches Jäger-Bataillon von Reiche. August Friedrich von Reiche served as Corps Chief of Staff under Han von Zieten during the Waterloo Campaign.
The Prince's governor, Oberst von Pirch II is Otto von Pirch and along with his brother Georg Dubislav Ludwig von Pirch they both served a lot in the Napoleonic Wars and were present at Waterloo. Some of Georg's performance as II Corps commander can be drawn into the issues at Waterloo section. Ernst Heinrich Dannhauer, who was friends with Reisswitz and played in the games, had service under Wilhelm von Krauseneck the Chief of the Prussian General Staff and von Krauseneck had extensive Napoleonic experience as well.
Even the mention of Johann Christian Ludwig Hellwig (forerunner to Reisswitz) in this article, which is also a good read,
https://kriegsspielorg.files.wordpress. ... _seven.pdf his son, Friedrich von Hellwig, also led a Freikorps with experience in the wars and was in command of the 9. Husaren Regiment under von Thielmann's III Corps at Wavre.
Von Müffling's glowing endorsement seemed to seal the deal on what a number of folks already knew, but gave it the official push.