Does anyone claim that what Nietzsche's heroes (and antiheroes?) will the return of isn't every violent human (or natural?) mistake, but some particular aspect of history?
It seems clear in context that what one is meant to be wishing for when wishing for eternal recurrence is the repetition of this moment now. The point is to always live in such a way that you would not want any alternative version of the current moment more than the one that is already happening, if you could back off and consider it in context for arbitrarily long, because this moment can be expected to lead into to moments you would wish never to lose.
E.g. one appearance is:
What, if some day or night a demon were to steal after you into your loneliest loneliness and say to you: 'This life as you now live it and have lived it, you will have to live once more and innumerable times more' ... Would you not throw yourself down and gnash your teeth and curse the demon who spoke thus? Or have you once experienced a tremendous moment when you would have answered him: 'You are a god and never have I heard anything more divine.' (The Gay Science)
The moments (in this case the ultimate single moment) you would wish to have return forever should offset every moment you might wish had turned out differently. Whatever others must suffer for you to regain those peaks is both largely irrelevant, and completely outside your power to control.