“If you look at the picture a bit closer there are at least three other people photoshopped in the cluster.”
If you were to see the original picture for comparison you can easily see there is more than that. Maybe 6 or 7. They are photo shopped in groups. One group is the girl in the light blue shirt and her friend next to her in the dark shirt.
AND there's at least six of a guy in a maroon shirt with his back toward the camera.
What!?!?!?
You are doubting the probability of several sets of sextuplets in attendance?