Here the 1920 LDS edition replaced every one with all, probably because the preposition among typically takes a plural count noun. Although every one is plural in meaning, its form is singular. The critical text will restore the original reading here, despite its oddity. There are no other examples of “among every one” in the text, although there are examples of among followed by all, including two cases earlier in this chapter:
There are no other cases in the text of the reading “among all of them”. More generally, we have examples elsewhere of “all of them” (six times) and “every one of them” (three times).
Summary: Despite its singular form, restore in Alma 28:5 the semantically plural every one as the head noun for the preposition among: “among every one of them”.