Different cultures of course have different norms. There were even hunter-gatherer societies that practiced extreme forms of pacifism - Moriori would be one example (and their eventual fate shows why this isn't more common).

In general, though, pre-agricultural societies tend to have very high mortality rates from armed conflict with outgroups. In PNG in particular, as I recall, it gets to the point where >20% of all males die from enemy action. Similarly, pre-agricultural societies rarely take prisoners, and often target what we would consider non-combatants (i.e. there's no separation between "enemy warrior" and "enemy civilian", even in principle).

And this makes a lot of sense when you consider what motivates this warfare. Pre-agricultural societies are bounded by the output of the wildland that they forage on, and a single human requires a lot of land to live off in this manner. This is why those bands tend to be small - very few biomes can sustain a foraging band of even few hundred. But conversely it means that any other band of humans foraging off the same land is literally starving you out. It doesn't matter if they are otherwise hostile or not, and there's no potential compromise to be achieved even in theory if you have a plot of land that can sustain, say, 100 people, but now it has 150 feeding off it. The only way for one group to survive is to either kill or drive off the entirety of the remaining group, so it doesn't matter if it's women or children that you're killing. The point is to convince the other group that they are more likely to survive by going elsewhere by making it so precarious for them to remain, or if that is not possible, then to wipe them all entirely. Raids do exactly that.

This is also why prisoners are rarely taken and often ritually killed right away - every prisoner you take is an extra mouth to feed. In an agricultural society, an extra mouth can feed itself because it requires comparatively little land to do so, but for pre-agriculturalists an extra pair of working hands is worthless if the land is already at capacity wrt what can be extracted from it (which is usually the case since populations grow until they reach that point).

Stuff like ethics of warfare, spiritual tradition, reputation etc is derived from all this. Cultures that practice this kind of raid warfare generally glorify it. A war leader who leads a successful raid to massacre an unprotected enemy village is a hero, not just to his own people, but more broadly as a model for other aspiring warriors in the larger culture. So things that we might consider as "disreputable" are not necessarily seen as such there.