At least my understanding of their "reasoning" was that it was literally a mass revenge in order to prove how strong and ruthless they were, so they did basically exactly what they intended to do. The only thing that could have been argued would have been better would be if they only killed the men or some shit, but thats borderline "military age male" reasoning. Slaughter is slaughter no matter if you try to save face by sparing the children.

And all the comparisons to violence in the middle of revolutions feels disingenous, cause that shit is during an extremely chaotic time with lots of shit going on and everything that has been built up overflowing at once. Lucanamarca did not happen during such a time, in fact in Gonzalos discussion of Lucanamarca he talks about how they couldnt have restrained themselves because otherwise the waters would not overflow like would be necessary for a revolution. Its just deliberately confusing individualist terrorism with state and mass terror against the bourgeoise and other reactionary classes.