Fundamentally, an EO says "we urgently need to course correct and do X", which only makes sense if you agree that X is not already being done.

So this EO is not just declaring "the Executive Branch will obey me", but also saying "the Executive Branch has been so disobedient that I need to take immediate action to quash that"

If you are saying that latter sentence, you should be able to justify it by pointing at the disobedience that caused this issue AND explain why the usual mechanism of "Congress passes a law to address the problem" is insufficient (AND congress is currently aligned with the President politically, so that's a fairly uphill battle to argue)

---

As an example, no one should ever need to write an EO declaring "the sky is blue." If you're familiar with history, you might remember that smog used to turn the sky yellow. If someone wrote such an EO back then, you could reasonably conclude the actual purpose of the EO is to declare "it is now illegal to notice that the smog is so bad that it's changing the color of the sky."