The idea of substates is certainly interesting, but I think limiting it to China is somewhat shortsighted, when this mechanic could be used elsewhere very effectively.
I can imagine applications for the British Empire, the USA (if not for states, at least for Philippines, Cuba, Puerto Rico), French West Africa (the French uniquely made some of their colonies actual departments, legally equal to other departments in France), and the Ottoman Empire (during WW1, for example, the British/French allied with the Arabs to defeat the Turkish and create the modern states of Lebanon, Syria, Palestine, Iraq, etc.)
Of course, for the above applications to be used, other considerations would have to be made. What's apparent in China now seems to be more like a 'marketing substate' than an actual substate or semi-autonomous region.
So far I haven't seen too too much from these DDs that makes AHD highly attractive, and that's unfortunate. Many of the features seem to be fixing problems from Vicky 2 (interface, colonization, reducing China's buying power). So next week give us something sweet and juicy to keep us salivating, yes?
