Ooh I was hoping someone would ask this.
They are the predecessor to the modern Zhuang ethnic groups. The history is interesting, albeit a bit weird and complicated, though I'll try to stay out of politics and all. So a bit of backstory first.
The Zhuang peoples are essentially an ethnic group that exists for a purely political purpose. Guangxi before the PRC was considered a fully fledged Chinese province, and a core part of "China proper" (whatever that's supposed to mean) by Han nationalists. The majority Han lived alongside 2 dozen ethnic groups, of which the largest were the Tong.
In 1949, the Soviet wannabees the early People's Republic were decided that China needed her own SSRs, inapplicability be damned. And so, the Autonomous Regions were born. Now the thing is, out of the 5 autonomous regions of China, 1 of them has a Han majority (Inner Mongolia), 2 of them have Tibetan and Uyghr majorities respectively, and the last 2 (most of the residents) have no idea why they aren't Chinese (Guangxi and Ningxia). From what a gather there are 2 reasons:
1) this essentially means in theory, most of China's major minorities want to stick with China.
2) it gives the CCP support from minorities, which the nationalist government under Chiang was...less willing to offer *cough cough* Taiwanese genocide *cough cough* aboriginals. A bit of a lesser of two evils deal for the Tibetans and Uyghrs. The latter of which I fear won't enjoy nationalists rule all that much given their rivalry with the Hui warlords.
But to justify this, the Tong and the couple minorities that lived alongside them were merged into the newly formed Zhuang ethnic group, and half of the local Han population was issued Zhuang ID cards, turning Guangxi into an autonomous province with a Zhuang majority.
Hopefully this offers a relatively neutral look at them. A bit hard to stay completely politics free I fear.
Does Hwang Mingyen speak Urdu as a first language? Does southern China have large Indian and Persian populations living in it?
Nope. Hwang just employs a large amount of Persian-Bengali advisors for his army.
Yep. They are mostly expatriates, though many have left in the wake of radicalism in China and Japan during the mid 20th century.
How is the US and the rest of the Americas doing?
The US's parallel ITTL is the British Empire. Here, it is a notably even more...Yankee state with a identity based upon the Atlantic. West of the Rockies, Imperial citizens have a bit of a "Siberia complex", so to say. They feel neglected, but the thing is there aren't all that many of them to constitute much representation at parliament. They also have a Cascadian independence movement no one supports.
The rest of the America's are generally in the British sphere, though the Euro-Mexican alliance is not shy about stirring shit up. !AltGran Colombia used to be a power that could effectively dominate South America, but now that the giant is coming apart at her financial seams, Gran Colombia doesn't look like it'll last much longer.