Well, the greenfield might be acceptable if THWN conductors are used, AND if arranged in such a way as to prevent water entry into enclosures. I personally like to avoid installations that require a "judgement call" on the part of the AHJ, and just use sealtite outdoors.
There was nothing said about lack of access to the opposite side of the wall. Properly securing stuff would be pretty difficult then. MAYBE toggle bolts might have a chance, but I wouldn't really trust them.
