the writer chose Shin for the purpose of freedom(not much known about him). the writer doesn't have to follow the actual events. there are already smaller scale events or facts that the writer changed. also this is fiction and not non-fiction, so basically if the writer wants it, we can see dinosaurs shooting lasers and yellow 5 headed dragons. it's not a documentary of the history of China. however that being said, i don't think the writer will change the major events.