As discussed under 1 Nephi 16:35, the determiner much can occur with plural nouns. There is, for instance, one example of much afflictions in the current LDS text (in Alma 7:5) as well as two in the original text that have been edited to much affliction. There are also examples in the text of the expected much affliction (four of them in the original text) as well as the systematically plural many afflictions (eight of these).
Similarly, we get variation in the original Book of Mormon text with respect to contention(s), with three occurrences of much contention, two of much contentions, and one of many contentions:
For additional examples of much occurring with plural nouns, see the discussion under Enos 1:21. The critical text will maintain each instance of the nonstandard “much ” whenever it is supported by the earliest textual sources.
Summary: Restore the original much contentions in the Words of Mormon 1:16.