Rav Chiya from Mishan was head of the yeshiva in Pumbedita after Rav Huna around year 4460. Many Geonim ruled, and Rash"b did not mention their names [(Tzemach David). And Shada"k page 36, section 71, after Rav Chanina from Mishan was Mar Yanuka, who is Rabbah bar Netura'i who died in year 4479. So too Yuchsin in the order of tradition from the Rama"n.

But they did not mention Rav Netura'i bar Rav Nechemya, and Tzemach David mentions him. I do not know in which matter to attribute the error (see above year 4448)].