The obligatory link: Howell rule limits choirs' sacred tunes
3.33 to 1? Aside from being an arbitrary limit, let's see how this works out in practice. I'll sing Rudolph, the Red-Nosed Reindeer, Frosty the Snowman, the Twelve Days of Christmas, and the first third of O Christmas Tree before I get in the first religiously-themed song? That's just the way I'd be tempted to do it, too. Y'know, just cut straight from the end of the first verse of O Christmas Tree to something along the lines of Joy to the World with no warning.
It's a silly rule at best, but if it can't be ignored entirely, work with it in such a way that eventually people will agitate for its removal.