It doesn't make sense philosophically either, IMHO.
Fuji is outright good, he even wanted to nuke Marijoa, hates the WG
and fought Ryokugyu to let the slaves (and the Rev) flee.
Kizaru has some gray shades, but Fuji doesn't. At all.
Ryokugyu seems more "evil", but there is that SBS to consider.
And that not considering that Zoro and Sanji fight yes n.1 and 2 of the subordinates, but there was always a huge gap between them. King was a YC1, and so a lot stronger than Queen. King was also formally higher ranked, and Mr.1 was to same to Mr. 2.
Admirals are not: there are not too wide differences and they have the exact same rank.