These are the sons of Zilpah, whom Laban gave to Leah his daughter, and these she bare unto Jacob, even sixteen souls
How about 16 kids????
God purposing an action so that it shall be sinful is not the same as God purposing an action as sinful. God purposed that some actions shall be sinful for the sake of the good that he will cause to arise from the sinfulness thereof. God purposed sin for the sake of the good that shall be accomplished. On the other hand, man purposes for the sake of the evil in wicked men.