Here the 1907 LDS vest-pocket edition deleted the first were also in this passage (changing “and thus were also those judges” to “and thus those judges”). This emendation eliminated the redundancy of the original text (where there is a repeated instance of were also at the end of the sentence: “and thus were also those judges … were also gathered together at the burial”). Like the 1907 edition, the 1911 LDS edition removed the were (probably independently of the 1907 edition) but neglected to remove the equally redundant also. The LDS text has continued with the 1911 reading, “and thus also those judges ... were also gathered together at the burial”.
Here in Helaman 9:11 the repetition of were also helps process the sentence since there is a rather long intervening relative clause (“which were at the garden of Nephi and heard his words”). There is evidence elsewhere in the text for this kind of verbal redundancy, especially when there is some kind of intervening phrase or clause; in the following example, we have a rather long adverbial by-phrase:
Joseph Smith, in his editing for the 1837 edition, removed the repeated hath from this particular passage; the critical text will restore it (see the discussion under Mosiah 10:18). A similar example of this kind of redundancy in the original text involves the repetition of the subordinate conjunction that and the restatement of the subject as a pronoun:
In that passage, the 1830 compositor (John Gilbert) deleted the redundant that he when he reviewed the printer’s manuscript prior to setting the type. On the other hand, there are no other examples in the text where also is unnecessarily repeated within the same clause (as it is here in Helaman 9:11).
Summary: Restore in Helaman 9:11 the original text, with its redundant were; also maintain the redundant also in this sentence; similar redundancies can be found elsewhere in the original text.