Priests in Vedic times were militant and priestly clans (such as Bhṛgu, Vasiṣṭha, Viśvamitra, etc.) maintained army of their own, which were affiliated to their respective tribes.
Bhṛgu was a priestly group of the Anus, Aṅgira, Vasiṣṭha, Viśvamitra were of the Bharatas.