> difficult for me to believe that they really got 10% top performers

It's difficult to achieve, but it's not an unreasonable objective to have. After that there is a question of measurement. How do you measure that? Did they? What was their score? - and yes, until the evidence is released, they probably didn't. (But I would also cut slack on the measurement - it IS difficult to measure so a decent attempt - a top 10% attempt? - will do.)

Where the "top performers" meme obviously fails is when every new business and their sister claims the same thing. We are all winners here and all that.