The issue isn't that they don't have enough percussionists, but that the ones they have are deficient. Making a wind player play an accessory wouldn't help that.

OP: If you want VERY simple tunes, the old red Essential Elements Christmas books have a few decent songs, but they're all block-chords, upper-voice melody stuff. Very early-90s band writing.

I would also recommend you look into a song like North Pole Sleigh Ride by Williams and/or for a bit more advanced, Name's Claus - Santa Claus also by Williams. In fact, Mark Williams has probably half a hundred pieces right up your alley here.

You could also consider one of my old standby pieces, At the Feast of Stephen by Watson.