With the exception of some massacres, committed by both sides, in the various Indian Wars, this was the massacre with the highest death toll in American history. Roughly the same number of people were murdered at Lawrence by Quantrill, but all were men and boys and therefore potential combatants, even if unarmed at the time, women being treated with the utmost respect throughout. At MMM women and children were slaughtered along with their husbands and fathers. IMO that makes it a greater atrocity. Do you disagree?
With regard to the Nazi comparison, please note that I said "in some ways." The death toll at Lidice was probably about twice that at MMM. And of course the total number killed in all German atrocities was many orders of magnitude greater, with the Nazi regime being pretty much an atrocity in its very nature.
But the comparison between the individual massacres at Lidice and at MMM is not entirely in the Mormon side's favor. This is primarily because of the cold-blooded and treacherous nature of the MMM atrocity. The Nazis did not pretend to be the Czechs' friends to get them to surrender on terms, and then violate those terms by turning on them at a pre-aranged signal and murdering them all.
Quite a few, perhaps most, women and children also survived the Lidice atrocity, while none survived MMM except a dozen or so very young children, allowed to liver because they were presumed to be unable to testify against the perps. To be fair, the Nazis later killed most of the Lidice survivors, more or less as part of their more generalized Holocaust.
Liver = live.
Sorry.
I consider the matter to be obvious based on common sense. It’s plain that the comparison of MMM - a one-time tragedy - with the even some of the atrocities of the Nazis - a systematic genocide - is well beyond the pale. If you cannot agree on that point, then we have no common foundation from which to form an intellectual discussion on the topic.