Some of these teams may include ninjas that you dont have (HASHIRAMA, wind blade, konan) but some of them so have f2p attainable ninja that you c*e to beat 108-120 Just my strategy
Followed your strategy for exam 120 with 3-3-2-2-3 + Ninja Dog Shiba and got it easily done, thanks a bunch now I can finally start upgrading my equipment :D