Bannon is infinitely smarter than Trump, and therefore that much more dangerous than Trump. Trump doesn't know, believe or care about anything, except about Donald J. Trump. But Bannon is the real deal -- a right-wing extremist, fully committed to white nationalism and the rest of the far right agenda.  To Bannon (and to most of the people around Trump for that matter), Trump is merely a useful idiot, a means to their ends. From their point of view, when Trump stops being useful, he'll still be an idiot and they'll bail on him in a New York minute. I would think that will happen at about the half way point in Trump's first (and only) term.