Yea every crew structure is a little different. To me i only use "yc" tiers as a general ranking to easily place a character. Example mingo i think he is yc3 cuz a fight between him and cracker or vista or jack is a toss up with the winner taking it at extreme diff.
I still don't understand the people that want the sh's to structure the crew like wb's or kaido's when he's supposed to have 1 of if not the strongest crew ever. The crew structure was never luffy far and away stronger than any on it with 3 characters separate from the rest. Luffy had 2 characters under him that were near him with a capable crew of specialists after them. This added 1 more in jinbe who jinbe being at least yc3 not confirmed luffy as a yc like crew. This can change even more if yamato joined and you'd have 5 characters on the "yc" levels on 1 crew with the rest being around or slightly above vet level which no other crew shown. Sh's are gonna be a better roger crew. Its imo going to be like shanks crew if it had mihawk but a step stronger.