Removing the thirsty people from the lightning image leaves brightness but loses the urgent need and disappointed expectation. Ignoring the books or their carrier in the Torah analogy likewise blunts the meaning of non-benefit.
The proper method of abstraction is to reconstruct both complete scenes first, then identify the set of relations shared by them. State that set as one connected respect.
This makes it possible to distinguish several independent likenesses from one composite likeness. Independent points can be assessed separately; in a composite point, removing indispensable elements destroys the intended configuration.