D&D is about as far from history as you can get in my opinion. That said, just because there is a setting conceit that is highly gameable, that doesn't mean you can't follow through that conceit in a 'simulationist' manner that does still look to real world history and real life for guidance in shaping how things pan out. I would argue playability is extremely important and having gameable setting concepts can mean the difference between a game that lasts a week and one you keep going back to for years (I think a lot of what has sustained D&D over its lifetime is it has many core elements that are highly gameable on a regular basis). But then moment someone like Hickman asks 'what is the vampire even doing in this dungeon', I would argue you are moving more towards something trying to model a believable world. Granted that is also where a lot of people point to more story elements to RPGs becoming significant in RPGs. I think both are true though, just as it can both be true that D&D with its setting of wandering heroes is there because it works for gameability and play over time, and that this can also lead you to ask questions about setting consistency, following the fictional history of the setting, bringing real world logic into the game etc. I don't think there is a one true way here. Some people want more cinematic D&D, some people want more realistic D&D (in the senes of things flowing more like real life and not being overly cinematic---or at least being perhaps more character driven). I think when you are dealing with fantasy especially there will always be players who will want areas of the game to be grounded in something real to help make the fantasy more believable (though I also think a Terry Gilliam style campaign is entirely fine too)