From the same article: http://www.meridianmagazine.com/bookofmormon/080227misunderstanding.html
Some misunderstandings have arisen from errors in the text of the Book of Mormon. A good example is found in Alma 43:13-14:
“the Nephites were compelled, alone, to withstand against the Lamanites, who were a compound of Laman and Lemuel, and the sons of Ishmael, and all those who had dissented from the Nephites, who were Amalekites and Zoramites, and the descendants of the priests of Noah. Now those descendants were as numerous, nearly, as were the Nephites; and thus the Nephites were obliged to contend with their brethren, even unto bloodshed.”
The wording of this passage, suggests that it was the “descendants of the priests of Noah” who “were as numerous, nearly, as were the Nephites.” In view of the fact that these priests had captured only 24 Lamanite women to take as wives (Mosiah 20:1-5), it is unlikely that they could have become nearly as numerous as the Nephites. I wondered if perhaps Alma 43:14 should read “dissenters” rather than “descendants.”
A check with the text of the printer’s manuscript of the Book of Mormon, from which the 1830 edition was typeset, showed agreement with the printed editions. But the original manuscript, from which the printer’s manuscript was copied, reads “de[se]nte[r]s,” thus demonstrating that the passage should note that it was the total number of dissenters who were nearly as numerous as the Nephites, not the “descendants” of the priests of Noah. The error was made during the copying of the printer’s manuscript, when the word in the original was misread.  ”
Tvedtnes is correct here, but for another reason: by this time, the seed of the priests of Noah–the Amulonites–had already had some problems, eh. This is in Alma 43, but earlier in Alma 25, we read that:
“4 And *among the Lamanites who were slain were almost all the seed of Amulon and his brethren, who were the priests of Noah, and they were slain by the hands of the Nephites*…
5 And *the remainder, having fled into the east wilderness, and having usurped the power and authority over the Lamanites*, caused that many of the Lamanites should perish by fire because of their belief—
7 And it came to pass that *those rulers who were the remnant of the children of Amulon caused that they should be put to death*, yea, all those that believed in these things.
8 Now this martyrdom caused that many of their brethren should be stirred up to anger; and there began to be contention in the wilderness; and *the Lamanites began to hunt the seed of Amulon and his brethren and began to slay them; and they fled into the east wilderness*.
9 And behold *they are hunted at this day by the Lamanites*. Thus the words of Abinadi were brought to pass, which he said concerning the seed of the priests who caused that he should suffer death by fire.
12 And he said unto the priests of Noah that their seed should cause many to be put to death, in the like manner as he was, and that they should be scattered abroad and slain, even as a sheep having no shepherd is driven and slain by wild beasts; and now behold, these words were verified, for *they were driven by the Lamanites, and they were hunted, and they were smitten*.”
Given also that no more mention is made of the Amulonites (other than Alma 43) and the fulfilling of Abinadi’s prophecy, I wonder if there even were any more Amulonites among the Lamanites after Alma 25; if there were, I imagine they didn’t number many. A more interesting comment from Tvedtnes would have been on why the mention of them in Alma 43, after Alma 25…