Why is Basil II separate from Rome, but Kublai rules over China?

[Karmah]

I can think of three reasons.

1. Most people, including most actual historians, consider the Byzantine Empire to be a thing. It outlived the rest of the Roman Empire by more than 1,000 years.

2. China doesn't like to admit that China wasn't always China.

3. It's more fun and fun is more important than consistency with regards which empires are really parts of other empires, or whatever.

Putting it in marketing terms

1. A case for 'legit' (even if only arguably)
2. Less risk
3. Fun for the game

So while I loved the discussion that enriches my own knowledge and with the uttermost respect for all those expert opinions, there is one line of arguments that I think is just wrong, is the one saying 'it makes no sense' , you can not tax this decision of being irrational . It does make sense for FX to have done it this way. Even you think you would have done differently for historical reason, which once again I respect.