How are apps ranked in trending apps

That's not proving that the 16k isn't included in the 400k. This is exactly what I see in my apps. If someone has cn > com then it proves

I doubt the cn numbers are passed to the com store.  What are your numbers for the same app on com and cn?

70k vs 3k

Of course. There is one example. https://apps.garmin.cn/en-US/apps/c430403e-6b89-4de5-af57-621d24c45b8c

20k vs 2k LOL

Never. I am sure the stats in .cn won't be passed to the com store. According to Data Security Law, apps.garmin.cn is locally deployed and the stats related to users' privacy should be stored in China Mainland

The above example. This watchface has more ratings and downloads in China mainland than that in Rest of the World. The stats in .cn store is not shown in .com store at all.