killing a villager is only last option. the whole tribe will cease and decease anyway if they can no longer produce babies for the next generations, since there is a limit in population and since in vv2, there is a limitation on the breedable age in women (in vv1, there was no limitation). the most important thing is continuity of the village from generation to generation. killing any one villager is only the last resort,if not doing so would mean death of the village, and not just an individual villager, if you would end up will all skeletons and no villager at all. a little sacrifice is worth it i guess. but again, it is only if you don't have any other option, subject to your evaluation as their god.