I asked this since I noticed that Jiayuguan, JUST the little subregion, has a population of 1.47 million times 4. Shanghai only has 65k times 4 population?
No, it's not. Even Istanbul has a smaller population than it did IRL.
Doesn't it only count the able-bodied men?
So women, children, and the eldery aren't counted?
It's the "times four" thing the OP mentions. The population you see in-game for each province should be multiplied by four to get the actual population, as is visible when you hover over the population tab.There is a "total population number" in the tooltip when you hover over the population tab, I believe.
I would assume the pop issues with Istanbul might be to nerf the Ottomans from very easily being more powerful than they were in real life at this time.