I know that I've seen a player play NJ without SoG in multiplayer so a different player could underdeck the soul that underdecks if opponent plays a good dominant, to prevent a winning rescue.
I also know that a certain national champion as my teams partner played his New Jerusalem from hand when he lost his Son of God to get his hand size down instead of just discarding it. The problem arose in that since he technically played it, I couldn't play New Jerusalem with my Son of God because our team had already played NJ.