With a fourth class multiclassing would make a tad more sense because 20 doesn't split amongst 3 evenly. I am still not sure how many levels I want to put into my Bard/Rogue/Artificer. But if I could add a fourth class then I know for a fact that my final build would be either Bard6/Rogue2/Artificer8/Sorcerer4 or I would switch the Bard and Sorcerer numbers depending on how it's working. In Paper and pencil games you can have as many classes as you desire. Can't we have at least 4?