Is it too hard for you to imagine Sanji having better durability than Zoro?
P1 wanted to go after Luffy and Yamato, yet for 2 weeks he shined with his absence in Wano. Sanji blitzed his ass over to sickbay, that's why. Either that, or the defeat he suffered was so overwhelming at any rate that his superiors would not have him continue the pursuing of the strawhats due to his setback. Killer was beyond recognition by Kid and his scythe does not lend itself well to the dynamic and highly mobile fighting style Killer is used to, so he was nerfed (Zoro too) but what reason do we have for believing Killer was treated nice with diners and fancy meals? He couldn't show himself in the capitol, and despite working for Orochi he was tortured alongside Kid in the prison. Killer was more nerfed than Zoro