I told Neji about this before, the battle system sucks. But unfortunately, there aren't any better battle system yet. My gyururu is a jounin with 50 attack & defend but still got beaten by an acedemy Student with not only less HP but much much lower stat than mine as well.
The current battle system just depends on luck too much. The power moves, the misses & the random damage done.
I can get flowless battles while doing suicidal search but got beaten to half dead by a level 14 enemy in the forest. Funny isn't it?