Today, I'm going back to the London Sound 70 Orchestra and Chorus Christmas compilation for observations on another unusual arrangement. How do you differentiate your version of "God Rest Ye Merry Gentlemen?" In this ensemble's case, you add the clopping of horse hooves to the melody, giving the carol a more percussive feel than it usually has. For good measure, you arrange it so that the orchestra and chorus sound like they're performing a lost number from "Fiddler On The Roof" during the third and fourth verses.
Those aren't the most obvious stylistic choices for "God Rest Ye...," but I don't deny that they work.