The priesthood of the cult of Sartar – that’s the Orlanth Rex for all the tribes of Sartar, aka the Prince of Sartar – is restricted to members of Sartar’s lineage. Generally the eldest son was acclaimed as the head of the family, following the example of Sartar designating Saronil as his heir. But not always – for example Sarotar and Rastoran both died before their fathers, and Tarkalor and Salinarg were acclaimed as the best candidates but not sons of the ruling Prince.
Kallyr’s grandfather was a son of Jarolar who died at the Battle of Dwarf Ford in 1557. Argrath’s lineage is even more distant – his grandmother was the Triceratops Queen, who was in turn the granddaughter of Onelisin the Cat Witch, the famed daughter of Prince Saronil, and the subject of many songs and stories.
These genealogies are going to be pretty well-known. Lots of Colymar knew Maniski and Yanioth Two Sight. Many more knew Arene the Triceratops Queen, whose herd of dinosaurs destroyed the village of Janastan in the Moaning Valley.