Sengoku was never directly compared to Roger, it was always Garp. Cornered Roger multiple times, beat Rocks pirates with Roger. Roger entrusted his very own son to Garp. Sengoku never had this kind of close-knit portrayal, he was always this mastermind strategist instead of a pure fighter like Garp.
Ranks means shit when powerscaling Garp, that’s already established.
I don’t know what coc has to do with anything, Roger and Rayleigh both have coc, one is still clearly stronger than the other. Garp/Sengoku ~ Roger/Rayleigh