It’s the Standard military designation. The Military are but the round likes longer barrels in standard issue. The QSZ11 uses the subsonic version.Do QSZ mean military or do police guns get that designation too? Aren't the military using 5.8x21mm? Maybe that round don't work with short barrel as it's more rifle like.
I really hate these racialist reasons. Same with how Japanese apparently can't handle full power 7.62x51mm even though Vietnamese who are considered even smaller and malnourished were able to handle 7.62x54r and 7x54 French .30 06 and even the big westerners preferred intermediate cartridge weapons hence widespread adoption. It always sounds like digs at the whole race as inferior for being unable to handle x or y, but nobody seems to ever talk about this supposed smallness as an advantage like being smaller targets and requiring less resources to feed. Slim grips are more comfortable for a lot of people in general, even people with big hands. It's all about getting accustomed to one or the other. I shot Glocks as my first pistols for a while and was what determined my standard for what a pistol should feel like before I fired a 1911 and I prefer the grip of the 1911.Depends on the design of the mag well and grip, but I have a feeling it might not be that simple.
The choice for single stack may well be to keep the magazine slim so they can make the grip smaller.
People of Asia are still generally smaller in size than Caucasians, which may make big pistol grips with double stack magazines uncomfortable to hold for an not inconsequential proportion of troops, which may be the reason for this design choice.