This is terrible logic and it continues to get worse with each post. Using this logic you can't really compare anything when using predictive measures.
You're essentially saying, "We can't compare these two scenarios because the defense could play differently, so we don't know which is worse other than pure math". That's a cop-out to the point being made. Why would a team ever punt the ball at the end of a game and rely on their defense for field-position, based on this logic? If it's not comparable due to a defense playing differently?
Ask any coach at any level of football, or any fan if they'd rather be in a situation where they require a 3-and-out from their defense or require stopping the offense from gaining 60 yards. The overwhelming answer would be the latter. But according to you, it can't be compared cause a defense may play differently due to situation.
The WP model is accounting for that.