They really have just been breeding farms. For every hundred grainoids that die an anonymous and easily replaceable death, we lose a trueblooded aryan. Breeding down is easy, breeding up is hard. Restoring good traits is definitely more work than turning them to shit. Let's also keep in mind that most of the people who died in wars throughout history did not leave behind heirs. It's a silly modern idea that every man must breed and have a wife. The TRVE trad way is that most men must never breed and die young.