Verses 5 and 6 conclude the introduction to the conditions existing before the great destructions. The government was destroyed “because of the secret combination of the friends and kindreds of those who murdered the prophets.” Even without writing the word Gadianton, Mormon clearly points to them with the indication that they operated through secret combinations, a phrase that also ties them to the Jaredites.
In verse 8 we have another place where Mormon will give a time, and then back up to describe events leading up to that time. Verse 13 of this chapter verifies that Mormon is still giving events of the thirtieth year.
The timing Mormon gives is also complicated because it does not easily fit into the declared dates in his text. The twenty-ninth year was when he indicated that they began to turn from righteousness. The six years Mormon mentions does not exactly fit in the timeframe he has given us. The Messiah will come to Bountiful late in the thirty-fourth year. He concludes the twenty-eighth year with peace, and has the beginning of the twenty-ninth as when “there began to be some disputings” (3 Nephi 6:10).
A possible solution is simply that Mormon saw the interval differently that we do. In English, if today were Monday, the next Monday would be seven days from today. In many Spanish speaking countries, the week is calculated as “de hoy en ocho,” or, literally, “eight days from today.” The meaning is precisely the same, but English does not count today, and Spanish does. Perhaps that explains Mormon’s six years when we see only five. It can also be understood by realizing that the clean divisions of events into years may not have been as clean as he writes them. Thus, the contentions might have been beginning in the end of the twenty-eighth years. The Savior appears in the end of the thirty-fourth year (see 3 Nephi 10:18, which occurs before the Savior’s appearance).