The Angelic Army — the uniqueness of Luke 2.13

At the men's Bible study last week, Bob asked whether there's a precedent for multiple angels/heavenly host appearing in the biblical record besides the announcement to the shepherds in Luke 2.13 and in the book of Revelation.  It is an intriguing question: Do we see other times when angelic beings make such a spectacular appearance?
A user-friendly website is www.BibleGateway.com where one may check the English Standard Version of the Bible for the following English occurrences:

• the plural form angels — ignoring instances of just two angels
• the two words heaven and host — which would include suffixed forms of these words
• cherub
• seraph

     This preliminary search results in rather few examples of multiple angelic beings making appearances together — and rather than to a group (such as the shepherds), all of these are appearances to one lone individual:

• angels were on Jacob's ladder — Genesis 28.12
• angels are revealed to Jacob en route to his reunion with Esau — Genesis 32.1–2
• the prophet Micaiah saw heavenly host standing on both Yahweh's right and left — 1 Kings 22.19 & 2 Chronicles 18.18
• Isaiah saw six-winged seraphim praising God — Isaiah 6.2–3
• Ezekiel sees four-faced four-winged cherubs — Ezekiel chapter 10; 11.22;
• angels ministered to Jesus after his temptation — Matthew 4.11 & Mark 1.13

There is also the episode at 2 Kings 6.15–17 where Elisha and his servant see a supernatural army of fiery horses and chariots, but there is no mention of angelic beings.

So Bob's posit was spot on: the angelic army's announcement to the shepherds appears to be unique in biblical history.