Literally only people very high in the sociopath end of the spectrum would think one gruesome kind of child murder justifies a different kind of gruesome child murder, to the point of using one to justify the other in an argument genuinelly believing other human beings will be swayed by that.

People in the normal human range within the sociopathy spectrum neither think “an eye for an eye” applies to the murdering of children - no matter the method used - nor think other people can be swayed to accept child murder by pointing out that child murders were commited by people only related to the former children by etnicity.

In fact normal people don’t even think one kind of child murder justifies the other kind of child murder even when the latter children have direct family relations to the murderers of the former.

You need to be quite the sociopath to merelly think somebody murdering children justifies killing their kids, and you need to be extremelly sociopathic to think somebody murdering children justifies killing kids of the same etnic group.

People whose psychological makeup is such that they trully believe child murder justifies child murder and, worse, that others think the same, need professional help, deseperatelly so.