This Datapack Adds Smite to all Greatswords, Hammers and anything that looks like a mace. Some of these weapons, like the Bone club may be weird to have smite on, but! but they are still considered Greatswords and to be honest, there is no proof there werent cave men Paladins.
While this modpack does nothing on its own, if you add minecraft dungeons weapons and spellblades n such, you can have smite on all of the mentioned weapon types!