They may practice more difficulty, but what team doesn't? Not every gymnast that attempts a DTY in practice is going to throw it in the meet. It's one thing when it's an individual competition, but when it's a team competition and every tenth counts, why be so risky as to throw a difficult routine that you're only 70% sure of rather than do what you know you can hit? Yeah, they could probably throw more difficulty, but then again.... they have four national championships. Only three other schools can say that. They must be doing something right.