If you understood how learning worked then yes, if you're a good engineer you will be capable of applying those skills and mathematics to whatever engineering p

If you understood how learning worked then yes, if you're a good engineer you will be capable of applying those skills and mathematics to whatever engineering problems they are - which doesn't exclude also hiring experts that are further along in knowledge and understanding than you and learning more for yourself. And you're right the engineering is similar but different, the real additional value comes from the CEO then making the right organizational calls - which he can do because of his engineering and prior experiencing starting and scaling companies. You simply disbelieving Musk is an engineer is you getting in the way of yourself.