Basically, my world's societies (They're tiny-sized for reasons too complicated to explain in a simple post) are forced to provide about 1 human sacrifice every month (Because reasons) and to fight each other in WW2-esque battles, leading to a high death rate for everyone. These societies are roughly 250 to 300 people strong.
So in the end my question is: Is it sustainable baby-making wise? I'm asking because I'm tremendously bad at mathematics and statistics; I've tried calculating the thing for 4 hours now, and I don't know if its because I'm stupid or because I'm making it too complicated for myself.
Also: Food and resources are not an issue, so women can potentially always be pregnant, and inbreeding mostly doesn't happen due to the high amount of migration between groups.