How much of your knowledge of game theory, FDT, and prediction markets/forecasting can you bring?
You wouldn't need to start with respect. People are much better at writing now than they were 100 years ago, on an instant-gratification basis. Plus, the Hobbit was 1937, I, Robot was the 1950s, Dune was 1965, so you'd be inspired by HPMOR and Three Body Problem and Hyperion while all your competitors would be running off of Frankenstein and Sherlock Holmes and Shakespeare. Not to mention real stuff like the Sequences, and the Extropian list, and what actually went down with the people involved in AI alignment from 2016-2023.
In 1904, the world's best behavioral economist was Sigmund Freud. Most people would quickly notice what they're capable of, after having nothing to do in their spare time but read Frankenstein and Sherlock Holmes and Shakespeare.
Write an awesome book about German greatness, optimize for maximizing troop morale, but explain things well enough that most German officers can understand it. If you depict the French and British as sufficiently stupid and crude, it will probably never occur to a single British or French person to plagiarize it and use it for their own side's propaganda. It would probably get translated word-for-word and get super popular in Britain and France anyway.