All cultures, even it seems primates, discriminate between notions of 'arbitrary murder' and 'justice' implying different things.

And it's all roughly consistent.

Arbitrary murder is always 'wrong' across cultures.

Self defence is almost always considered reasonable and a form of justification.

Even basic cultures developed sense of 'justice' as retribution or punishment.

It gets a bit more complicated in terms of organized violence, but even there, it's generally always considered moral in the posture of defence, just as it were a single person defending themselves.

For other things, it's more complicated.

And of course 'war parties' and 'arbitrary retribution' has always been there, aka 'they slighted us, we harm them' absent true moral justification. That's always been problematic, admittedly.

Also "and the whole thing is written via dictation from a war god." this is not an appropriate assertion (not nice or welcome)