That's the problem. It's pulling from many inspirational sources from early wargaming as well as reconciling early RPG systems such as OD&D, Holmes, Moldvay/Cook, and AD&D 1e and 2e. Too many to list out. Bath and Featherstone and Barker will all be part of the DNA. I still need to dig into Diplomacy variants too. A lot of D&D founders were part of that movement and culture.