Comparison of Lists in Ezra 2 and Nehemiah 7

While reading the list of returning exiles in Nehemiah 7 something jumped out at me finally (it hasn't happened before despite reading this Bible several times)--"Hey, didn't Ezra just include this listing as well?" Then I wondered why the editor hadn't combined those readings since that's what he does when there are duplicate sections. I paged back to the September 23rd reading including Ezra 2 and briefly compared the lists. They are very similar yet differ at some spots. For example, the names will be appearing the same in the same order and suddenly a number will be different. There are a couple possible reasons for this:

1. The Concordia Self-Study Bible says, "Many of these differences may be explained...by assuming that a cipher notation was used with vertical strokes for units and horizontal strokes for tens, which led to copying errors."
2. The People's Bible and Kretzmann's Popular Commentary both attribute the discrepancy to the lists being tallied at different times. For example, the Ezra list may have been compiled as the exiles assembled for the journey while Nehemiah's list was a copy of those that registered upon the return to Jerusalem (some may have gone straight to their homesteads instead of registering).

Other points about the discrepancies of the two lists:

• Sometimes when names are different they are variants of each other--Bani/Binnui, Mispar/Mispereth. This is like what we do in English--Richard/Rich/Rick/Dick, Margaret/Maggie/Marge/Meg.
• Since both lists are summaries and not complete lists, Ezra and Nehemiah might have each chosen differently what to include or not include at certain points.