Funny that you ask this question. I was just talking with my father the other day about this type of issue (he is a lifelong elk hunter in Idaho). His answer is always the same: Take a fat cow over a bull any day, because "cows taste better than rutty bulls."
I realize the cows in your picture are adolescents, not mature cows. I guess it depends on your perspective, if you are a horn hunter or a meat hunter. But there is nothing wrong with passing on a big bull to take a big cow.