My degree is in history. I hold that genre in particular narrowness, and note that it's one of the very few that can't be played - because the academic definition is the only proper history. If you can't document it, it's not history.
Anything else is a different genre; history is, by nature, definitionally required to be non-fiction. Add any fiction, and you're no longer in the genre of history.
"historical gaming" is inherently NOT HISTORY... it's gaming informed by history, but it's a different genre from history.
Historical fiction is also a different genre than history.