China is drowning in debt and is one of the most debt ridden nations. In the last five years since the global recession, their economy has acquired more debt than any other country in world history in such a short span of time. At the rate they're accumulating debt, they're likely to become the most indebted nation, as their fake growth requires ever more credit per dollar of growth they're able to generate. They can either keep faking growth with debt, or they can crash.

Both their muni debt and their corporate debt are the highest in the world on a GDP basis. The two of those together are at least $15 trillion right now (and that's if you believe their numbers, it could be far worse).

Adding China would just drastically increase the amount of debt in the GX group.