וְיוֹאָ֥ב בֶּן־צְרוּיָ֖ה עַל־הַצָּבָ֑א וִיהוֹשָׁפָ֥ט בֶּן־אֲחִיל֖וּד מַזְכִּֽיר׃
And Joab the son of Zeruiah was over the host; and Jehoshaphat the son of Ahilud was recorder.
Rashi
and Shavsha was scribe Ahilud was the recorder, and Shavsha would write alongside him.