Natalia Wotjowicz has written an excellent book called Wargaming Experiences about approaches to professional wargame design informed by her experience with the NATO Civil-Military Cooperation Center of Excellence. Her book offers a lot of guidance relevant to both historical games and wargames, so I invited her to discuss it along with differences between professional and commercial design.

Books by Natalia Wojtowicz:
Wargaming Experiences (2 book series) Paperback Edition (amazon.com)
Outro music: Marnie Stern "Plain Speak"
The Comeback Kid | Marnie Stern (bandcamp.com)