EXACTLY! Zabuza beats Darui.
Anyways I actually think Mifune takes this. He is faster than Darui and won't let Darui weave a sign so his Ninjutsu is useless. He is superior to Darui in Kenjutsu so he is the most probable victor.
Btw, do u think Zabuza beats Mifune? I mean, Zabuza is an excellent swordsmen and hidden mist jutsu only takes 1 hand to perform and he can wield his Kubikiribocho with one hand. The mist only takes seconds to start so Zabuza will be able to stall in time to activate it.
If Darui was able to use ninjutsu with one hand then he'd take this