Roll film does not allow N-1 (unless the scenes are the same type). Thus, Ansel Adams does not come to the rescue here.
Try to forget shadows here: we all know that fill light lightens them. I am talking about the SUNLIT portions of the scene and to simplify, let's focus upon ONLY a grey scale fully lit by sun. Would exposures in either case be identical or different. I think different. - David Lyga