No Gintoki is the strongest of the Joui war remnants not only strongest physically but also have the strongest will to live(evidenced by Jump fiesta special flashback), Katsura already given up his life by dying and taking as many enemies along with him while Gintoki says otherwise.
Gintoki didn't get his Epithet Shiroyasha for nothing
- - - Updated - - -
But if the fight goes on Okita will be a goner for sure
Kamui have a really twisted personality, he loves to fight and have so much more blood thirst compared to other Yato, his Father Omibozu & Housen