Hi Epaminondas,
Just thought I'd nitpick.
3. I wouldn't call the steppe nations conflated with China - that's only the case for late TC, which is in any case pretty heavily sinicised. The steppe nations are absent from MA, but in EA they're represented by Sauromatia (I know, from the opposite end of the Eurasian continent).
4. Isn't C'tis very loosely based on Egypt?