I like the green & grey together. I also like that each of the images could stand on its' own without the words. the words as a group look good, good font choice.
#22 is my favorite because it communicates group (two people) and growth (upward arrow). I like #20 as well because of the upward arrow. #17 is interesting because of the circle image, but I am not a fan of the way the people look in the circle in #17 and #18. They look a little bit like ghosts to me.
I like what you did in #21 but because it's only a single person, it doesn't communicate group as well to me. Thanks for your work!