I shoot a lot of ducks with a 20 and we even hold a couple of sub gauge goose hunts a year. But I don't care what anyone says I've never seen geese crumple like they do when getting hit with a pad of big pellets from a big 10
Try hitting them with a wad of lead-like #2's from a tightly choked 12/16/20 too. Dead is dead.
Sometimes we get bored and do sub-gauge days- 28's and .410's. It calls for will power to wait and shoot until they're within bayonet range and pass up edgier shots do-able with a heavier gun, but again dead is dead.
