Just as falsification tells us what may be true by that which we cannot make false; and proofs tell us what is not false but not what is true; and the law tells us now what we must do, but only what we must not do; and evolution tells us only what fails, not what succeeds, it is not important that the best people lead, as much as it is important that the worst do not.
For this reason we must limit access to power to those least likely to lead poorly. How do we know? Demonstrated character in familial, entrepreneurial, political, and military excellence over multiple generations. And the elimination of consideration of those who fail the test of character in familial, entrepreneurial, and military excellence across multiple generations.
Nobility is most frequently demonstrated by intergenerational excellence. For those who cannot master their passions enough for good breeding, good rearing, good production, and good defense, have demonstrated by their actions that they and their families are unsuitable for leadership.
Note that survival from the opinions of others in schooling, academy, politics and church, tell us nothing about an individual other than his ability remember and to obey, while engaging in various forms of politicking and deceit. Only family, commercial, and military experience tell us about the capacity of an individual to lead.