Barahir, Lord of the House of Beor?

To be honest, I’m pretty confused too. So, here’s the situation: Barahir was the second son of Bregor, previous lord of the House of Beor. So when his father died Barahir’s brother Bregolas became lord. Barahir had a son, and Bregolas had two, so both brothers had heirs. Yet, when Bregolas dies in the Dagor…