Looking at his parents, I can’t believe he is in the military at all
That’s why everyone is suspicious: why encourage this nutty kid to join the military when he could have joined the Peace Corps? I suspect he was encouraged to cause trouble.
He was home-schooled but couldn’t get his GED until he was 20+ which, in turn, explains why he took so long getting into the Army. And that makes the case for the low level of geniousity evident in the Bergdull house.