I'll give a 5/10
Considering Kavalier is supposedly a trillionaire and one of the world's most intelligent guy, he recruits the biggest idiots going
That is probably quite realistic, especially given what he did to his father and the age he did it.
A lot of very "smart" people are incredibly dumb in anything outside their field, and a lot of exceptionally rich people are utter idiots when it comes to listening to advice. He is the epitomy of that, he's had no one to talk sense to him since he was a child, and he's very deliberately surrounded himself with people who will do what he says (or have to do what he says because they're programmed to do that), and any humans that disagree with him are utterly expendable.
There is a reason we had Court Jesters and IIRC one of the roman emperors had a slave whose job was to remind him that he was in fact still a mortal man, without someone there who can tell you "this is a very stupid idea" or "this is going to get you killed if anything goes wrong" a lot of people with who have a huge amount of power/money will make incredibly simple and stupid mistakes because they think they know best and no one can tell them they're wrong.
The Soviet union fell apart (as do most disctatorships) in part because you get to the point where they literally "kill the messenger" if the news isn't good, so you get entire organisations or countries where the information that goes up the chain is always "you were right boss" and "your plan worked fine".
IIRC there are several models of small, private aircraft that have the nickname of "doctor killers" or similar in the US, because wealthy doctors/lawyers etc who might be very good at their job get a pilots licence, get (barely) qualified in higher performance (more expensive) aircraft then think that because they're really good at their job, and they've managed to pass the test they are better than their instructors who aren't as brilliant and wealthy as them...It often ends up with the pilots lack of experience causing them to run out of luck by moving to a higher performance/harder to fly aircraft before they've mastered the normal starter Cesna etc fully.