Ross Geddes (personal communication, 22 September 2004) wonders here if they should be ye. The surrounding text uses the second person plural pronouns ye and you, as noted above in bold. In support of this emendation, we have the following case of they that was emended to ye in some LDS editions early in the 20th century:
In this case, however, the use of the subordinate conjunction that (“that they would in nowise be delivered”) allows for a shift to an indirect quote and thus a return to the third person plural that is used in the surrounding text. For further discussion of this case, see under 3 Nephi 3:15.
Here in Helaman 14:4, 𝓞 undoubtedly read they since both 𝓟 and the 1830 edition are firsthand copies of 𝓞 for this part of the text. If they is an error, then it must have occurred as Joseph Smith dictated the text to Oliver Cowdery. The problem with the emendation ye for they in Helaman 14:4 is that these two pronouns are phonetically and orthographically dissimilar, so it seems unlikely that they would have been mixed up. (This conclusion also applies to the case in 3 Nephi 3:15.) In fact, there is no independent evidence for mix-ups of ye and they anywhere else in the history of the text, neither in the manuscripts nor in the printed editions. There is one case where it appears that the two pronouns ye and we were mixed up (in Helaman 13:25), but these two pronouns are phonetically and orthographically similar.
Ultimately, it seems that the original text occasionally has shifts in person. As an example of this, see the discussion under Alma 56:52 regarding an example where the shift in person covers at least a whole sentence. Although the shift between second and third person here in Helaman 14:4–5 is somewhat jarring, the text itself remains understandable. Perhaps Samuel the Lamanite momentarily distinguished between his current listeners and those who would observe these events five years from then. Despite its difficulty, the critical text will maintain the shift in this passage from ye to they and then back to ye.
Summary: Maintain in Helaman 14:4–5 the shift from second to third person (from ye to they) and then back to the second person (from they to ye).