Rashi: Now it lists those who signed testimony about accepting the Mitzvos.

Malbim: On the revealed Sefer, their signatures were in this order - the most esteemed were first. In all, 83 signed, like the 70 of a Sanhedrin and 13 appointees that the Rambam writes - the Segan, two Katikolin, seven Amarkelim and three Gizbarim. The Kohen Gadol did not sign.

Rashi, from Yerushalmi Kidushin 4:1: It is Nechemyah. He is called ha'Tirshasa, for Chachamim HiTiRu (permitted) him to drink (SHeSe) Yayin Nesech ¹ of Goyim; he gave to the king to drink.

Ibn Ezra (Ezra 2:63): Perhaps this is a title of grandeur in Leshon Kasdim, like Sar or Pechah. This is primary.