to be fair, he is likely the strongest one since he rivaled oden himself. the other 8 got nothing close to his feats.
and since oden even hurt kaidou, then shuten maru must be at least YC1, while the other scabbards I doubt are even on par with YC3.
I just quote you, but this comment is not only for you.
Btw. Shutenmaru wasn't Odens rival. It was said that Oden beat him, Nothing more Nothing less.
You guys ignore/Forget some Facts here.
Shutenmaru fought with Inu
equaly! so he is as strong as Inu and Neko. This argument alone is enough, to see that they are equaly strong. Carrot also said it. And his feat against Jack is basicaly the same, as Inu's and Neko's feat against him. They all could Show some impressive feats. They are able to fight him, but not to win against him. And this was against his human form, not hybrid.
In shutenmaru's and Jack's clash, we could see that Jack could push him away, overpower him. Shutenmaru is not stronger than jack or at his level - they can't beat a human form Jack, but this guy also have a hybrid form, which will make him even stronger.
Hybrid Jack > Human form Jack > Shuten, Inu and Neko.