^ ALL Speculation as Tsunade was shown to fuel his jinton. Show me a single scan of Onoki using it anywhere near that level. Any where near. Yes, because Tsunade is such a speedster to avoid Sasuke's high-speed attacks.
Why exactly he can't? because he never showed it? Lmao,Do u think it is a valid reason to say that he can't? This reason is as dumb as saying that Sasuke needs Naruto's chakra to pull legged Version of Susano

noki needed help of Tsunade when he is low on chakra not when he is perfectly restored, so he can do that with his chakra pool unless U can give me proper reason as to why he can't do that insted of using he can't use it because he never used it BS.
He can't do that only if the amount of chakra that jutsu uses exceeds that of Onoki's pool,Onoki is low on chakra and so is Tsunade as she lost consciousness after awhile so there is noway in hell for them to pull much chakra in that condition.Inorder for u to prove that he can't use it u need to prove me that that jinton takes more chakra than Onoki's chakra pool otherwise don't even bother to reply.
There is no need fot Tsunade to avoid those attacks, rest of the Gokage can provide protection for them,B4 attacking them with his Super speed attacks Sasuke needs to deal with a huge sand wave covering his Susanoo.