Top talent, I would think, are people who deserve to be at the best of the best law schools (however you define them) and I would assume everyone expects to become the best lawyers, judges, academics, etc.
It doesn't change the discussion much, I don't think, however we define able. Since none of us live in a vacuum, let's define it as in their own lives, but give them the benefit of having had their ultimate goal since freshman year of high school being admission to a top law school.
Also, keep in mind we're talking in generalities. Sure there was probably some super-genius who could have killed the LSAT, but he was distracted fighting lung cancer, sudden blindness, and the death of a loved one. This is clearly neither the norm nor illustrative of any generality we might make about admissions standards.
So, [in general] should top talent be able to have a high LSAT/GPA?
Edit:
Be able to in a grade-inflated major or in a very rigorous program?
Doesn't matter. Admissions counselors tend to adjust based on major and university. A 3.2 in mechanical engineering at MIT is higher than a 3.8 in business admin at Joeblow Tech.