Why does it discuss the days of Yoyakim?
Rashi: He was Kohen Gadol. The others listed are the heads of the Batei Avos.
What do we learn from "li'Srayah Merayah"?
Rashi: Merayah was the head of the Beis Av of Serayah's Mishmar. Similarly, Chananyah was the head of the Beis Av of Yirmeyah's Mishmar, and also the others listed. The verses do not teach about all 24 Mishmaros.
Ibn Ezra: The prefix Lamed teaches that Serayah was a head to Merayah, or vice-versa.
Malbim (1, 12): The coming verses list the new leaders of the 24 Mishmaros. Above (10:2-9) listed 22 of them who ascended with Zerubavel the first time and signed on the Chasum. Here it does not mention Chatush's Mishmar, nor who was appointed in place of Minyamin. However, it says in Perek 3 that Elyashiv was Kohen Gadol when they built Sha'ar ha'Tzon. When they made a Bris to guard the Torah (Perek 10), how did all the previous Sarei Avos sign?! Either (a) This episode was when they ascended in the days of the first Koresh, or (b) They ceased to be Sarei Avos due to old age, but they had not died. They were more esteemed than the new Sarei Avos, therefore they signed.
