(23) В¶ Now Joab was over all the host of Israel: and Benaiah the son of Jehoiada was over the Cherethites and over the Pelethites: (24) And Adoram was over the tribute: and Jehoshaphat the son of Ahilud was recorder: (25) And Sheva was scribe: and Zadok and Abiathar were the priests: (26) And Ira also the Jairite was a chief ruler about David.
Observe, Joab retains his post. David did not, or perhaps could not dismiss him. Some alteration had taken place in David's officers since the establishment. 2 Samuel 8:16-18.