Kakashi solos low difficulty.
Part1 Kakashi? Who barely defeated Zabuza? I doubt that.
OT: Team Kakashi still wins with low difficulty. War arc Sakura probably solos if Suigetsu has no water source.
No Suigetsu beats Zabuza mid difficulty.Zabuza is much stronger than Jugo, Suigetsu, or the non fighter Karin, so I'm not even seeing your point here. He has all the tools necessary to take this low diff.
-Sharingan Genjutsu to disable Jugo.
-Raikiri for Suigetsu.
-Basic Taijutsu for Karin.
No Suigetsu beats Zabuza mid difficulty.
OT: Team two wins low difficulty.