Retard scaling demo (how Lufftards, Lawtards, Sanjitards and Kidtards scale):
Captain > Crew member
Standing next to each other = equal
Luffy's enemy (captain) is always > Zoro's enemy (crew member)
Now combining this we get
S-Bear > S-Hawk so Kuma > Mihawk but we already know that Mihawk is > Shanks so Kuma > Mihawk > Shanks. One more thing since Kuma is a subordinate of Dragon hence Dragon > Kuma but then Shanks is also a captain so Shanks > Kuma. The final result:
Dragon > Kuma > Mihawk > Shanks > Kuma