lul .. let me mimic you for a moment ..

...why? why did they give Lightning Main immunity and can attack multiple times in 1 round if he c*ready attack two times with bloodthirsty.

...why? why did they give Earth Main round 1 shield and can add another shield and make all ninjas attack two times and add another shield.

...why? why did they give Fire Main super control skill and can reflect debuffs and make all ninjas immune to debuffs.

...why? why did they give Water Main healing skill and give super poison and chaos to enemy at the same time.

.. Let's be serious here, the game will not work if they did it unbalanced, yeah maybe from your prospective but if you know how to use your character then those balance/unbalance theories will be gone .. That's the reason also why each ninja has its own set of skills and abilities, to comply and support each one another and build a harmonious team that can go all along better ..