1st son was named after the father's father
2nd son was named after the mother's father
3rd son was named after the father
4th son was named after the father's eldest brother

1st daughter was named after the mother's mother
2nd daughter was named after the father's mother
3rd daughter was named after the mother
4th daughter was named after the mother's eldest sister

*This pattern is not set in stone. For instance, it was considered bad luck to have 3 people with the same name.