Hey,

Do you have any heavy damaging ninjas or rare ninjas in general? There was a lineup which I used in a low power account using Kimimaro, Earth Main, Asuma WB and Sakura cloak. Also, classic wind main teams with Gaara do work as well if you have Minato Hokage or Jonin. Takes some tries and luck to beat these and it also depends on your power and how much the difficulty was decreased.

Try Fire main with Gaara, Iruka and Six Paths Naruto. Fire main with mirror and reflect, make sure to cast him both times the right time and you'll be fine. Round 2 make sure to be able to bomb Gaara as well, be patient and cast fire main's mirror and afterwards use Gaara .

Hope that helps