This society traces its lineage through matrilineal lines, with witchcraft being exclusive to the female line. Ritual magic involves using the mana of the world and directing it in a way to suit you .It requires chanting, numerous ingredients, and a group of people depending on the spell. Society has evolved to raise boys in bulk for their unskilled labor, and are considered "sons of society". Girls are kept at home by their mother for proper training in witchcraft and are referred to as "daughters of their mother".
Family units are important because they provide for the needs of indiviuals and introduces them to the broader social structure of their world (sex and companionship between adults, raising and rearing of kids, protection from threats, etc). The classic "two parents + children" is common because it naturally organizes around human reproductive patterns and fulfills these requirements. This setup is unique in that it raises boys and girls differently due to magical ability. I need to make this system culturally viable over the long term to meet these needs. How can I do this?