I can't rule out the possibility of even better results with the squatting ... but I rather doubt it. He used a rather unorthodox deadlifting style which was more akin to a hybrid squat-deadlift. I don't think most trainees realize how much quad stimulation the deadlift affords. And my son's style was even more quad-dominant.
I never sought to correct him because he doubled his starting weight before I even saw how he was doing it and also because it was evident that he was protecting his lower back. So, who was I to mess with providence when my little boy was deadlifting 2.5 X bodyweight via a slightly unorthodox style ? It wasn't like he aspired to be a powerlifter anyway.
Nowadays he doesn't even deadlift. Rather, he maintains his physique by cruising, doing pretty much what he wants, when he wants to do it. And the only legwork he usually does are lunges, step-ups and the like.