Problem with that tactic is late game the healers will either stun you or use a high atk guy to one-shot your squishy * with a jutsu.

It's all about supports. I've even seen highly competitive teams at level 100+ using nothing but supports. If they can shut down two of your guys, heal all their guys, and beef up an invincible counterattack tank like mister Sharkspammer (Kisame) or someone who dodges everything (Gai) then you're only waiting for autoattacks to kill the enemy for you because you have all the time in the world.