Hearts of Iron 4 just turned a "dangerously shippable" idea into a new system of frontline command, with a splash of HOI 3

The next Hearts of Iron 4 DLC, 'theater pack' Thunder At Our Gates, is all about "the art of organizing a campaign." Along with expanding on the potential for Australia, Siam, and Indonesia to act as key players in the WW2 grand strategy game, it allows you to deploy generals into local command positions using a new system of Military HQs. As developer Paradox explains, this went through quite a few iterations, including input from the community and some inspiration from predecessor HOI 3, to reach where it's at now.