The law of large numbers would indicate that yes, a cross section of the 'smartest' should have the same racial make-up as the population. If it doesn't, then something is rotten in the state of Denmark, so to speak.
This is absolutely false. Cultural upbringing isn’t uniform across all cultures. This has more to do with higher education than anything else. Look at the percentage of Nobel prize winners who are Jewish. Look at the Jewish population.