Kuro, extreme diff

Zabuza, low - mid diff. One water prison and ts all over for kuro.

Zabuza, neg - no diff.

Smoker is the only East Blue character I could see as jonin level

No one can harm smoker without haki

He def has a weakness that we don't know of, kinda like Crocodile and liquids.

Either way I was just arguing that no other East Blue character has the feats to be jonin level

Yeah but the thing with kuro is that one move where he goes berserk and slashes everything. also that one move is capable of easily slashing cliffs and rocks