Some world class Olympic lifters have unreal leg development, which also can includes the glutes, that can over shadow their upper body's in terms of development (except maybe for trap and lower back development). Seems to happen more in the light heavyweights on down, more so than the upper classes. For any of them, the foundation of power is in the lower body.
Sounds like Santasy has selective genetic's for larger muscle mass in the legs. Not that uncommon really, most of us have body parts that seem to have a mind of their own, where natural growth is concerned. Even the smallest amount of work can add mass somewhat faster than other parts.
Might suggest Sassy Squats for awhile, which may bring a totally new shape to the legs themselves, without (hopefully) adding more size. A very old form of squatting is to squat on the toes, which spreads the work load to the calves a little more. Might be worth a shot. (stubborn calves have been know to respond to on the toes squats..plus improving balance) Or you can choose to make a career out of huge legs, like Tom Platz did, for years. Good luck.