Here scribe 2 of 𝓞 did not clearly write the plural s for two occurrences of Jews and the first occurrence of Gentiles. It seems that in each of these three cases he tried to write the s, but it was never clear, so we have to consider the possibility that the singular was intended (Jew and Gentile ).
But the s for the second occurrence of Gentiles is definitely there. The parallelism here implies that at least both occurrences of Gentiles should be interpreted as plural. We do know that scribe 2 of
𝓞 frequently dropped his plural s ’s (for examples, see under 1 Nephi 13:23). In any event, the two occurrences of what may be the singular Jew is possible. Nonetheless, Oliver Cowdery, when he copied from 𝓞 into 𝓟, interpreted the whole passage in 1 Nephi 13:25–26 as being in the plural (two occurrences of Jews and two of Gentiles).
If the singular reading Jew is what scribe 2 actually wrote, he may have been influenced by the two occurrences of “the mouth of a Jew” in the previous verse (1 Nephi 13:24). Throughout this part of the text, we have seven examples of the singular Jew, but in each case the text refers to “the mouth of a Jew” (or “the mouth of the Jew”):
But in 1 Nephi 13:25–26, there is no reference to “the mouth of a /the Jew”.
There are other places in the text where the singular Jew occurs. Here I list all other occurrences in the text of either singular Jew or singular Gentile. In most instances, they are found together:
Only in the last one do we get the singular Jew occurring with the plural Gentiles. Note that we also get the plural brethren as well as the plural “all ye ends of the earth”; thus here in 2 Nephi 33:8–10, this contrast between the singular Jew and plural non-Jewish people seems intentional.
Summary: Accept Oliver Cowdery’s transmission of the plural nouns Jews and Gentiles in 1 Nephi 13:25–26 since parallelism supports the plural in this passage.