Considering he didn’t go into that field and choose to do adventure tourism in space or research in space, I’m betting he couldn’t hack it in that field either.
Hmm, I remembered it slightly wrong. He had a career as a pilot and flight-test engineer, and set records for being certified on certain planes the earliest of anyone, but it looks like you're right, he wasn't ever a design engineer. He went into the business end of aeronautics after that.
The submarine thing came out of a midlife crisis, which is another disturbing part of it.
I'm not going to bother arguing over the definition of "smart". Natural language is fundamentally imprecise. How about we just agree that he made bad decisions and call it a day?