I would say it is evidently true to me. As stated, humans are fragile. A punch or fall can easily cause brain injury leading to death. Get in an advantageous position on a person and they are going to have a real hard time preventing you strangling them unless they're trained/experienced in hand to hand fighting. On a purely physical level it is not hard to kill a person. This isn't even considering assistance from tools or infection, where a direct kill from fighting isn't required.

The number of people capable of this isn't 100%, sure, but it's closer to 100% than your posited 10 in 1000, 0.1%