That flexibility is there so POTUS isn’t self limited in their selections and they can pick who they’ll work with best to best ensure national security. Hes replacing someone who may have been put in position due to their race, which can be a national security concern when you hire like that.
Yet he was the only current Chiefs that is Black, if Biden was promoting because of Race why is the other Chiefs White? Could it be (wait for it) Merit rather than race? And if he was the DEI pick how come trump promoted him to be the first Black to head the Air Force in his 1st term? NOT DEI
