I don't really get what's the big deal with fire main. Yeah he's the best at early game you can say that due to that mirror skill. But as level progresses, the growth rate of his potential to be the best is average. Unlike water mains, Earth mains, their start is very poor we all know that. But their growth for potential to be the best class is very very high as the level progresses. Do take note that each class has their own asset that can outshine one another.

I'm not theorizing or anything. I am a water main. I surely remember back when I got 14k power (free to play), I beat people who topped up like crazy who has 17k power fire main. That's the highest, also fire mains above my power gets beaten with ease. They have to spend more crazy amount of ingots to overwhelm my tactics since they are unable to outsmart me. It's just a matter of knowledge and technique to strategize well enough

I'll give you a water main as my lineup against your theory-crafter FM lineup.

Talents: 3/2/3/2/2

Hinata x x
x x x
WM-Kakashi-Naruto

Any first inflicted damage is a counter to FMs mirror. And you worry about Neji as the first move? Wait for him to cast acupuncture mystery and heal it with your main's heal mystery. It costs 0 so you are able to initiate another mystery. Neji acupunctured your water main? Then initiate as well. Take him down asap, next is FM then naruto then gaara. In the first place, if you have higher refine (naruto at least), your theory-crafted lineup is wayyy no match to a basic WM setup