This is so wrong.

First of all, you are being disingenuous by presenting a generic image for "militant Christian" and "militant Muslim" but a whole bunch of specific individuals for "militant atheist." If you were intellectually honest you'd have provided specific names for the Christian and Muslim categories. Of course, if you were to do so the "militant Christian" and "militant Muslim" categories would quickly grow to far outweigh the "militant atheist" category.

Second of all, I don't know the biographies of all those people but I know enough to say most of them were not "militant atheists," the core of their ideology was not atheism and the atrocities they committed were not in the name of atheism. Marx is a hilarious example since he was simply a philosopher and social scientist, never did anyone any harm really. And again, he was not a "militant atheist," he happened to be an atheist and he criticized religion but that was a very small part of what he wrote about.