Regal Tweedledee and Tweedledum Salt and Pepper Shakers

Ok, so given that there are 4 variations of Alice shakers in the Regal tea set, why on Earth did they do yet another set of shakers?! Tweedledee and Tweedledum are also a true set, with either 2 or 4 holes in the back of their heads. Their names are applied to their collars in gold, and it frequently rubs off being applied over-glaze.