As Chris Mellon has said, the DOD is so stovepiped that some of what is going on never gets to the top and is never shared with anyone outside the few that know.
Then on the other hand, as you have said, there is hidden shadow government (perhaps even another world) wherein many people are involved.
I'm not sure what to believe about all this.
If you dig deep into the lore on this it looks like family members (generations) keep the secrets.
It is a lot easier and safer to trust relatives who are raised with the secrets than to bring in new people.
My view is that if President Trump needed to know something he knows who to contact to get that information.
Joseph P. Farrell has written some great books on this stuff.
John Warner IV (son of the former Senator and Navy Secretary) also discusses this a lot. He was the “rebel” in the family so they stopped trying to recruit him—but not before he got a good understanding of how the gatekeeper structure works.
The system works more like a Secret Society than what we normally think of as government—or even business.
Regardless of your security clearance—you are either in—or you are out. If you are out you will get fed either disinformation or very limited disclosure.
That is why standard briefings are totally useless in this area.