It depends on plants. Sometimes I've found myself spending way too much time on getting wood or background components just perfect and then realizing that I didn't leave room for some of the plants that I wanted to use. So if you're using some larger terrestrial foreground plants, might want to back the wood up a bit. If you want a larger vine on the background with some smaller epiphytes on the wood, bring the wood forward... and so forth.
I actually think it's really cool looking wood and all of the layouts look great, just looking at the wood. I just thought I'd mention really thinking about what plants you're going to use and their placement, since I've "underthought" in that area at times.