How is the track record for christian ones any better, then? 130 million os worse than 17, sure. I can get down with that. But, the figure is likely 130 million and 17 million because of the respective populations of the world at those times. If there were twice as many people in Germany during Hitler's time, it's believable, to me, that the number killed might be close to doubled as well. likewise, if instead of, generically, there being a population of 1 million people in 50BC, there were 7 billion, then that 17 million number, I'm guessing, would be a lot higher.
That isn't to say one murderer wipes out 1 person in a room of 10, and another 10 in a room of 100 are equal, if they wanted that specific number. But, if you commit genocide on a city, the number dead can only reflect the population at the time. With god behind them helping in the killing, had there have been more non-believers around, their numbers would be higher.