You are undervaluing the power of 40% resistance buff from minato in arena.

This last fight is the perfect example of the 'hey i am a whale with no idea of what i do and i hope it works' kind of person. Obviously you won.

That said remember also that people are used to metas so when something is different or if you use a not well renown lineup they go in tilt.

For example yesterday i went in training arena with the usual mei, mabui, tenten gnw lineup with a single slight difference. I did not select the uusual talents. Result? Better i do not tell you, if not you do it too.