i dont know which healer is the best.

sakura sailor is the best for most cases for now

kabuto is top for a curse mark team.

Tsunade is well the best don't have anyone else.

Totally depends on your lineup

Sailor sakura - aoe attack (synergy with poison tai), burst heal
Tsunade - semi tanky with her self burst heal, but problem is this heal is only useable R3.
Kabuto - can generate clones, though they are pretty much a non factor in most matches now unless you're really facing 4 single target ninjas

Problem with Sailor Sakura and Tsunade is they only debuff 1 per round, and its the lowest life guy, so if someone vital like ur initiator gets controlled, he might not get debuffed on sakura/tsunades turn.
Kabuto is more passive since he has no standard attack, but he does debuff/heal 50% of ur team compared to 25% from sakura/tsunade.

Ultimately depends on ur main/offensive ninjas and what role type of healer you need. Do you need burst heals? Tanks? Clone shield to soak up/distract in r1? You only have 3 choices, play around with them to figure out the strengths and weaknesses (although TBH, IMO sailor outshines the other 2)

but overall in mata now sakura is best.

as she can heal(a lot) and damage too.

if ur main is water u can pick sakura sailor for the healer n posion team its work well.

thanks :):)

Sakura Sailor is the best until Hokage Tsunade comes out (I think she should've been in the Kage treasures)