Or maybe they're not used to the game at this level where the machinations are far better planned with bigger time horizons than in the real estate world. The world of international politics is a shark tank that you don't just jump into.
I don't think that makes Trump, Jr. dumb or suggests that he lacks foresight but if you don't play this game regularly then you're going to get taken for a ride in the beginning. It certainly didn't help that he was seemingly surrounded by people who were doing similar stuff but with greater understanding of the consequences.
The law and my limited experience with politics are nowhere near that level of complexity and even now I'm surprised by the depth of the games within games over seeming minutia that politics deals with and even the law, known for it's love of minutia, doesn't come near.