Shanks, BB, Aokiji, Akainu then it is pretty random.
As a whole yonkos are better, way more different from one another both look wise and character wise. With the admirals you have these 3 officers with the sane attire, they all have powerfull elemental logias and character wise you have the rightfull Aokiji but who left the navy after it fall under Akainu, the merciless pirate slaughterer Akainu who is almost a villain and then the no care giver Kizaru. Character wise are paragonable to yonkos yet the other points are too standard.
Yonkos are way more developed, rivalries but also temporary alliances which can turn at every point. Characters like Shanks and BB, you don't even know their true purposes, also they are way more important for the story, and have more and better story in the manga, giving importance to their yonko status too.