It was a combo, but it was mostly Shaq's size and talent. Keep in mind that Shaq had some pretty productive year in Cleveland and Phoenix, too.
Unfortunately, players with Shaq's size, talent, and instincts / experience are exceedingly rare. I thought it was silly when some fans thought that Chris Wilcox could replicate Shaq's offense, and I'm equally skeptical that any draft pick in our pick range can bring what Shaq could.