Though we're now off the topic that was started, because Neo and Enigma were talking about modern historical fiction, not about fiction written during those time periods. Those are two different arguments/topics completely. One is about how we in the present filter the past, the other is about how the past filtered the past.
So if we look at modern historical fiction about Japan, it's all about lords and samurais. Whereas the fiction from ancient Japan includes Momotaro, and Issun-Boshi: stories of childless poor peasant families who get a magical kid who makes good. And Kintaro: some kid of good birth, but who was brought up in a mud hut on a mountain by a scraggly old woman. In Momotaro the poor couple find a giant mutant peach floating down the river and decide to eat it. Eating some suspect shitty food that you just found at random isn't a pre-occupation of the nobles, but it makes sense if common folk were re-telling the story.
I think western historical fiction is actually similar. Mostly is all about kings and knights. You see very little of normal people's life. e.g. D&D has adventurer classes, and "commoner classes" are basically a joke - a mere afterthought to the heroic level system. Sometimes you get a parody like Monty Python, where the trope name "Dung Ages" is appropriate, but even this is a parody/cliche, seeing non-nobles as filthy insane vermin rather than real people who actually run the country.