The wild card is that most of these people will not go down for each other.
Hegseth is paranoid and insecure on two levels. First, he and Trump lost their absolute shit when Kelly and the others put out that video. Called for their execution or prosecution. That is somebody getting caught with their hand in the cookie jar and now we know the cookie jar is Venezuela. Both Trump and Hegseth radiated guilt and Trump put it out there that Hegseth told him whatever he told him, so Trump has put it squarely on Hegseth's head. Hegseth knows MAGA will turn on anybody Trump says to turn on. Hegseth very clearly fears that some officer will go up in front of Congress and testify and that video scared him, and now he's couched the language he's using in reference to these strikes that he and Trump thought were popular. He thought that Franklin Turtle thing was cute, now he realizes it wasn't well-received.
The second level of insecurity is that Hegseth is still, at heart, an Army major. Him threatening to do a uniform inspection of Kelly was, as others have said, the most POG thing somebody in Hegseth's position could ever do. That was an Army major who has never held a major command and felt like he was disrespected and by gawd he's going to make the person pay.
Combine all of this with the fact that every day, Hegseth is surrounded by people who had far superior careers to him and that has to wear on him. Think about it - he makes major and is pushed into the Individual Ready Reserve, which is weird as fuck to me. He managed to get into the D.C. National Guard but wasn't allowed to participate in Biden's inauguration because of a dumbass tattoo. He only had about 10 years or actual military service, and part of that was National Guard, which great, kudos to him for joining, but at the end of the day, he had a very scattershot career with multiple gaps in service.
And you can bet plenty of Navy, Marine, Air Force, and probably even some Army senior officers all look down upon for him because his military career seems to have went nowhere, and they will all still think of him as a major that never held a large command and that was jumped up to Secretary of Defense.