The problem, TBD, is that you have put up a strawman.
We all agree that what China is current doing is horrendous.
We just don't think it has anything to do with atheism (or Marxism, for that matter).
Harping on how bad things are in China does strengthen your argument, since you are running in open doors when it comes to condemning state violence.
Hence the real question: do you think that, all other things being equal, the membership in a religion would stop the leadership of China from being so oppressive?
Your answer (if I got it right) is that as long as there are any Atheists in China, they would continue the violent attacks.