I could feel something was off. Another look at the fragment and I realized I put the limmus of Zeru-ibni and Tab-šar-Aššur on two separate lines when in fact A3 shows them on the same line. Thus my reconstruction of col. III needed fixing.
I'm not exactly sure what to make of this because it would seem that the scribe who made A3 believed Zeru-ibni and Tab-šar-Aššur were one calendar year not two consecutive limmu years. He did not put them on the same line in A3 (col. iii, line 6') for lack of space on the tablet, so the only explanation I can think of at this time is that Zeru-ibni died in office or was replaced by Tab-šar-Aššur who finished out the limmu year as a suffect.