The idea of measurement is a great take on the subject. I'd like to envelop that in a "brute force" argument, which to me is common sense and available to everyone. You need to have the big picture in mind before getting into the details.
SOCRATES: Have pleasure and pain a limit, or do they belong to the class which admits of more and less?
Understanding and being able to explain clearly to an ordinary person why asked that question, and why Epicurus' answer would differ from that of Plato, is key.
First step back and compares the competing worldviews of "Platonic Forms" to the worldview of "atoms and void and none other." You must think completely outside of (discard?) the Platonic worldview in order to fully understand Epicurus, even though Epicurus does the work to refute the Platonic worldview. The Platonic worldview is one of mysticism, which has no place for Epicurus.
Nothing material is perfect. Here's a minor reworking of Seneca, to emphasize this point:
"Therefore the power and the greatness of virtue cannot rise to greater heights, because increase is denied to that which is [a Platonic Ideal]. You will find nothing straighter than the straight, nothing truer than the truth, and nothing more temperate than that which is temperate. 9. Every virtue is limitless; for limits depend upon definite measurements. Constancy cannot advance further, any more than fidelity, or truthfulness, or loyalty. What can be added to that which is [a Platonic Ideal]? Nothing otherwise that was not [a Platonic Ideal] to which something has been added. Nor can anything be added to virtue, either, for if anything can be added thereto, it must have contained a defect. Honour, also, permits of no addition; for it is honourable because of the very qualities which I have mentioned.[5] What then? Do you think that propriety, justice, lawfulness, do not also belong to the same type, and that they are kept within fixed limits? The ability to increase is proof that a thing is [not a Platonic Ideal]."
Read in this context, PDs 18-25 are each about not getting caught up in the Platonic worldview.
So from that perspective wanting to be Zeus would be a natural but unnecessary desire - unnecessary because while the variation is desirable, we can live approximately like Zeus while we are alive and say we have tasted the same thing. Frustration at not being perfect doesn't become an enemy of living a good pleasant life.
This might even be considered an unnatural desire, since it's arises from the groundless opinion that you can achieve perfection. But from these two PDs it seems to be open to debate whether it's natural or unnatural, but not that it's unnecessary:
PD29. Among desires, some are natural and necessary, some are natural and unnecessary, and some are unnatural and unnecessary (arising instead from groundless opinion).
PD30. Among natural desires, those that do not bring pain when unfulfilled and that require intense exertion arise from groundless opinion; and such desires fail to be stamped out not by nature but because of the groundless opinions of humankind.