John Gill Commentary Genesis 36:29

"These are the chiefs that came of the Horites: chief Lotan, chief Shobal, chief Zibeon, chief Anah," — Genesis 36:29 (ASV)

These [are] the dukes [that came] of the Horites
Not that succeeded one after another, as the kings next mentioned did, but were together, at the same time, heads of respective families, and governors of them; and then the seven sons of Seir are rehearsed in this verse and (Genesis 36:30) in their order, with the title of "duke" annexed to each of them, "Duke Lotan"