The above epistle was written sometime before the final battle between the Nephites and the Lamanites when all but twenty-four of the Nephites were killed. Moroni was with Mormon at that time (see Mormon 6:11). Therefore, this scripture is inserted here because it fits into the chronology and the content of what Mormon 5–6 are describing.
The three men mentioned by Mormon who had been killed in battle (Moroni 9:2) are not identified elsewhere. They were undoubtedly faithful soldiers under Mormon’s command with whom Moroni was acquainted. The last phrase of verse 2 begins with “yea,” which identifies other choice men who had been lost with these three men, and thus these three men were also choice men