I had an argument with my mother over the phone because she was trying to tell me that the Witnesses preach the entire world. I asked about China and it stumped her. Several days later we were talking (arguing) on the phone again and she told me that "she asked an elder and they said the reason that China is not in the annual report is because it's all underground there."
So there is no reason arguing if they are just going to bring up unfalsifiable claims. Even if they had a thousand people there, which I highly doubt, it would serve no purpose other than to endanger the lives of the thousand.