The question though, still remains" How does Bob's triptych make any more sense than most any other photo which almost has to include these three elements to have any chance at success? I understand his creativity, and understand why he chose to go with three images...but I am not sure I understand why he didn't choose to put all three elements into one image.
Chris,
Compositions only make sense of they work. The ideas in Bob's triptych or fresh. Repeating the motif of the leaf arrangement in color B&W and different texture can potentially work. One can also have everything in one picture or only one of the three.
But then there's much more, for example when the forms evoke connections to cultural or natural iconic symbols or mythology or else colors elect emotive experience. The possibilities beyond color, form and texture are endless.
You already have so much more on your esthetic menu: trees, rain, lack of machines and the list could go on.
I would agree that completing the form of the proximal vegetation to the ground would provide powerful anchors to the composition and more softness behind would add to the distinctions, if that fits in with your vision.
Maybe explain your ideas a little more if our responses are of track.
Asher