Why not make each panel in the top image a module? The forked pieces could be straightened with very little stretching, but save a bunch of texture space, you could even weld the seams, reducing the overall vertex count. Why not stack a lot of UV's on top of each other? You have 3 texture sheets when all of this could fit…
I'd go with tiling textures for this. You would save a lot of time on unwrapping and on painting the textures. It will also be easier to tweak the textures later if you need. I find it a pain in the ass to work with unique uv sheets for stuff like this. You might need to change your geometry later and you won't have the…