Pitch, or indeed much premeditation at all, wouldn't be necessary in a village with five foot alleyways and dried grass roofs. Additionally, tar was a common caulking material. Oh, and running water/chemical foam wasn't usually a thing. And, you know, no trained quick response teams, or well maintained roads and swift transit systems to escape on, or any way to tell the difference between the smoke that always hung around the fireplace and the smoke from the roof being on fire... I could go on.