China's population density is about the same as Europe's, and was lower for much of human history. China's just bigger, land area-wise. In 1800, China's land area was 5.1m sq miles. Its population was 300m. That's about 58 people per sq mile. Whereas the UK's land area was 120,000 sq miles (including Ireland) and its population was 16m. That's another way of saying that the UK's population density, at about 133 per sq mile, was more than double China's.
That hasn't changed. Even today, China's population density is about half the UK's.
Well, discounting the Gobi and other parts not easily populated.
The areas that support a population are more densely populated and have been for a while.
Rice produces more food/acre than wheat, rye or barley.
https://en.wikipedia.org/wiki/File:World_population_density_1994_-_with_equator.png
Your premise would make an interesting research paper. The effect of population density on the outcome of peasant revolts.
I wonder what that map looked like during the middle ages prior to the plague years...
