There is a book called An Outline History Of China which is available in english and might talk about this topic, I haven’t read it myself but it seems to take a very Marxist approach to history. We also have a history of China page on prolewiki which is mostly based on a series of lectures Ken Hammond of PSL gave back in 2004. It’s a very materialist reading of history but not super Marxist, but that’s where I heard about the people that switched between settled and nomadic back and forth, though he only mentions it as an anecdote.