The third (corrected) printing of the 1905 Chicago missionary edition (in 1907) removed the subordinate conjunction although and the subject pronoun they in order to eliminate the original incomplete clause in this passage. Such editing is consistent with other editing in the text, although there are still examples of incomplete sentences in the Book of Mormon (see, for instance, under Enos 1:3 for discussion regarding the incomplete sentence in Enos 1:1–2). The critical text will restore here in 3 Nephi 7:7 this instance of an original incomplete sentence. As explained in the previous discussion, Mormon added the although- clause here to reverse the incorrect meaning that resulted when he accidentally wrote the word righteous in the preceding phrase (“insomuch that the more righteous part of the people”).
Summary: Restore in 3 Nephi 7:7 the words although they; these words are part of the original text, even though they create a sentence fragment; here Mormon attempted to immediately correct the noun phrase that he had just written by adding this although- clause.