I'm sure when you look at the finished image, most of what I say is already apparent to you, but here are my thoughts. Perspective plays a major role when doing a group this large, with a big distance between the closest individual and the farthest individual. The closer someone is to the camera, the larger they appear, the farther they are, the smaller they appear. I would have put all of the smaller skiers in the very front, and worked my way to the very back with the largest/tallest. You could have also added some room by having the entire back row stand, as well as a row to camera left. As it is, you have a number of faces blocked by people in front of them. I would also have everyone remove their helmets and goggles, you can't see their faces that well, and the helmets take up more room, blocking people behind them. You also have a number of heads stacked behind the head in front, always look to place heads in the gaps between the 2 people in front of them. I can see by the look on most of their faces that they were probably a pretty rowdy group, and it's a lot easier to critique a photo after the fact. I shoot hundreds of groups a year, and I am still amazed when I'm processing my images at some of the things I missed when I was shooting.
Randy Brister, Cr.Photog.