Some good images here. I think #59 is too "blunt". After further thought I think we're looking for an image that conveys "small parts make up the optimal solution". I'd say that #61 (as well at the highest ranked #38) come closest to this. I like the shades of blue and orange in #61.
We like #88. I'd like to see this with a darker blue and slightly brighter orange. Also maybe some variations where the two interlocked shapes look more like subtle arrows.
#87 looks good but the orange downward shapes seems to dominate.