One comment that I'd make is that Kingdom sets out to emphasise and dramatize the gap between the aristocracy the lower people. I recall a feast during the first series where the aristocrats were gorging on chicken and tossing it around, almost eating like animals-like gluttony as a contrast with the lower classes. The villages you're being shown are more akin to leper colonies than normal villages. The artistocrats are being portrayed in a way that's supposed to make you dislike them. That's not to say that it's complete fantasy but there is dramatization at play.

Another thing to keep in mind is that the settings takes place after the period of the imjin war, i.e. the japanese invasion of 1592-1598. In the drama it was supposed to be the case that a great victory against the japanese had been achieved by turning the peasants into zombies and setting them against the japanese troops. The country was devastated and the japanese engaged in widespread looting and wanton destruction when they were forced to retreat. This caused widespread famine because food production had been severly disrupted.

Normally period dramas used the "traditional folk villages" as sets. They've also become tourist destinations now but when they were first organized they were supposed to be repositories of historical buildings from across the country. You can get some idea from videos like this. I couldn't find a more history specific footage but it should give you some idea.

I always advise against taking dramatical portrayals as literally true. It's a common mistake for non-koreans that only experience korea through dramas to ask for example if bosses are always that nasty and if workplaces are full of shouting and slapping. You can find places like that but taking it as representative is absolutely wrong.