Moroni does not explain how Shiblom’s grandson, Ahah, regains the throne for his clan. The narrative is increasingly stripped because the pattern carries the meaning; all Moroni needs to give us (though, unfortunately, not all we want) is the tersest sketch to confirm that pattern.
Chronology: The average-reign chronology of thirty years places Seth at 380–350 B.C. with Ahah reigning from 350–320 B.C.