Hey~
Best ninja for ranked, in my opinion: Kabuto, Chiyo, Hinata. Why? Kabuto will literally bring someone back from 50 health, it happens to me fairly often. Chiyo can revive ninja not on her team. Hinata is just tanky - putting her across from Lee, Zabuza, Suigetsu, earth team w/ super lightened boulder essentially makes 1/3 of their taijutsu useless.
Otherwise, I'd suggest having leech in there somewhere (useless if ignited but even a few HPs are helpful), interrupters, debuffs like poison/ignite, debuff clears on your side from Sakura (let her get the heal in 1st round because it'll automatically go in 4th round then, when you need it more) and lots and lots of shields/clones. And don't use teams you need to babysit unless you tailor them to an opponent after a challenge (Ino will Chaos randomly unless 1. you tell her not to, or 2. the immobile-r she's comboing after is across from the desired target, like my fire's passive sleeps.)