What does 1 Chronicles 1:51 mean?

And Hadad died. And the chiefs of Edom were: chief Timna, chief Aliah, chief Jetheth,

Hadad died also. And the dukes of Edom were; duke Timnah, duke Aliah, duke Jetheth,

And Hadad died. And the chiefs of Edom were: chief Timna, chief Aliah, chief Jetheth,

And Hadad came to his end. Now the chiefs of Edom were: the chief of Timna, the chief of Aliah, the chief of Jetheth,

And chiefs of Edom are: chief Timnah, chief Aliah, chief Jetheth,

And after the death of Adad, there began to be dukes in Edom instead of kings: duke Thamna, duke Alva, duke Jetheth,

And Hadad died. And the chiefs of Edom were: chief Timna, chief Aliah, chief Jetheth,