In the Mouth of Three Witnesses

Moroni now prophesies about the three witnesses.  This may just be straight prophecy (telling the future), but given the temple context of the preceding chapters, I can't help but wonder if three witnesses had a role in the Worship of the Shalems.  Maybe the high priest had three principal angelic assistants when he came out as Melchizedek to administer the bread and wine, and those assistants were witnesses... maybe the three witnessed the various oaths of the ordinance... if something like this were the case, it might connect the calling of Peter, James, and John to Jesus' identity as Yahweh, the great heavenly high priest of Israel whose coming was foretold by the feast in the hekal.