I wouldn't say 6's are out of touch with their intelligence so much as they are out of touch with their own confidence. I consider myself to be an intelligent person, but I know that having to apply that intelligence sometimes makes me nervous if I'm not totally confident in what I'm saying.
Also what would anybody know about there being an E8 ISTp out there? It seems like a weird combination to me but I'd like to hear other opinions on it.