If we accept evolution and natural selection (or if we don't then fine), but if we do, then to quote Darwin ...
"I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection"
It seems reasonable to presume that pacifism did not always exist, that it did in fact come into being as a 'slight variation" and since it seems to have been preserved, then, according to Darwin, it must be useful. Of course we would have to acknowledge that any ideology, while useful to some will be deemed a threat to others, and thus your example of the Hutu.
The argument is that because pacifism exists, it must be useful and that usefulness must be a source of protection for the pacifist. No?
The fact that something survived doesn't make it a source of protection.
Acne survived, does that make it useful against muggings?
Stupidity survived, does that make it an effective force for self protection?
Look back at the historic record - it tells the whole story, if you leave your imagination aside.
I'm not saying that pacifism, or any kind of breathing/meditative work is bad - just that it won't help you much in the kind of situations that we're discussing. If you think it will - then no need to get on the mat at all.