It is very difficult to define the level of ODEN, his Ryoy is praised today by KAIDO, he is praised for being a monstrous samurai, the fight was in the castle, the pathetic way that the ODA made the second part ruin everything.
The fight would begin when the monster rose, but Oden fell asleep after the monstrous bludgeon.
Furthermore, we do not know how many days the castle fight could last until orochi actually convinced oden.
Oden found a loophole created by the kaido who underestimated him, Kaido found a loophole created by the author and an old woman who fucked herself. I already said, oda didn't want to tie up the whole fight, it ended quickly.