The barbell squat is a great exercise, make no mistake about it. Be aware that even though all the athletes on a particular team are doing the same exercise they are getting variable results based upon their form or body position.
Changing a lever system by only a few degrees not only dictates how much you can lift, but also which muscles you are using to move the load.
One technique to effect body posture is bar placement. Moving the bar from the front of the shoulders to different positions on your back certainly effects results and what musculature is used to raise the body and weight upwards.
In the below leftmost photo the athlete moves the load with little extensor help. As the angle of the back is changed from about 170 degrees up to 110 degrees, the amount of extensors that are being used comes into play. Obviously, in a weight room some athletes are doing more quadricep work then others and some more hamstring work then others, purely based on their body angles.
Coaches spend a great deal of time teaching stance, posture, flexibility, and bar placement to get into a powerful position to move weight.
Look at the powerlifter squatting on the Pendulum Squat Pro below. If he were to bring his feet 4-6 inches forward he would also change the angle of his back about 5 degrees. He would in turn load his extensors. The amount of weight raised would be reduced, but the desired effect would be acquired by increasing the muscular tension on the targeted musculature. He may move less weight, but would Get very Strong.
This can be done on the Squat Pro, with very little coaching as Pendulum's floating yoke accommodates posture.
The bottom line is that Form Dictates Muscular Growth.