I've been racing cars and superbikes for 35 years. Absolutely, positively, less weight = quicker acceleration, quicker deceleration and higher cornering speeds. What could be better for your ball-count than carrying higher cornering speed around and out of the ball, followed by quicker acceleration? Everything else being equal, it can only make you wider and earlier. Wide and early = time to shorten the rope.
If a skier including gear weighs 200 lbs. then loses 20 lbs., that is a 10% weight reduction. The engine in a light formula car is about 10% of the overall weight. Make a spec race car THAT much lighter and you'd slaughter the competition ... then get disqualified cause weight is the first thing tech checks at the end of every race. Weight is THAT important to speed and cornering, and slalom sking = speed & cornering.
I'm convinced weight is Nate's advantage. Sure his technique is great, but he's not the only guy with great technique. I'd bet that his advantage is the best reach-to-weigh ratio on tour.