If you read the vishnupuran there are various stories of how khastriyas (warriors) became teachers (brahmins) and vice versa. Even ashwatamma was called the son

If you read the vishnupuran there are various stories of how khastriyas (warriors) became teachers (brahmins) and vice versa. Even ashwatamma was called the son of a brahmana, his father was Drona, a Brahmin, but he was referred to as a son of a Brahmin because of his alliance with the crown prince Duryodhana and deeds he was determined more of a warrior