Just my experience,

I have kept father and adult son in the same bin with 3 females with no cannibalism, I separated the son out finally with his own females to find him later eating his pinkies. That is the only time he did that. I have had females eat babies also. I believe stress to be the main trigger if it only happens once, just make sure it doesn't keep happening.

I do harem breeding and have a spare bin where I put moms who need to gain weight and weaned pups so they aren't draining mom who most likely has a new litter to feed anyway. If they are looking thin, I soak the rat blocks in Ensure and feed that for extra calories. They get Mazuri 6F as a staple and then leftover table scraps when available.I never separate nursing or pregnant females from males, I simply do not have room to separate each and every female.

That said, I do care about my rats a lot. And treat similar to how I would a pet. If they are suffering for whatever reason, I humanely euthanize and feed them off.