In the transcript for 𝓞, in order to fit the text into a rather long lacuna in the manuscript (of about six manuscript lines), I proposed that the last sense-line here in Helaman 16:12 was initially omitted in 𝓞. I have no specific evidence that it was this part of the text that was initially skipped in 𝓞, contrary to the claim stated in the original discussion under Alma 4:20 in part 3. For a full explanation, see under the addendum for Alma 4:20 here in part 6 of volume 4. The critical text will, to be sure, maintain this long phrase at the end of Helaman 16:12.
Summary: Accept in Helaman 16:12 the final phrase “in the eighty and ninth year of the reign of the judges” as part of the original text; there is a possibility that it was initially omitted in 𝓞, but there is no specific evidence that this is the phrase that was actually omitted initially in 𝓞 for this part of the text.
Since the should was restored to the LDS text in the 1920 edition, the critical text will maintain, not restore, the should in 3 Nephi 1:8.
The discussion of the spelling god without capitalization is actually found under Mormon 9:10–11, not under Mormon 9:10.
The phrase “both of the Nephites and of the Lamanites” should directly postmodify the noun armies; thus the sentence should read as “there should be armies both of the Nephites and of the Lamanites … should be placed as guards”. The dashes should occur around only the parenthetical phrase “or of all them which were numbered among the Nephites”. Thus the third and fourth lines in the citation should read as follows:
both of the Nephites and of the Lamanites
—or of all them which were numbered among the Nephites—