Albert Barnes Commentary 1 Chronicles 7:20

"And the sons of Ephraim: Shuthelah, and Bered his son, and Tahath his son, and Eleadah his son, and Tahath his son," — 1 Chronicles 7:20 (ASV)

The sons of Ephraim - The genealogy is difficult. It is perhaps best to consider Ezer and Elead (1 Chronicles 7:21) not as sons of Zabad and brothers of the second Shuthelah, but as natural sons of Ephraim. The passage would then read as follows:

And the sons of Ephraim, Shuthelah (and Bered was his son, and Tahath his son, and Eladah his son, and Tahath his son, and Zabad his son, and Shuthelah his son) and Ezer and Elead, whom the men of Gath slew (that is, the settled inhabitants, as contrasted with the nomadic Hebrews, Amalekites, etc.).