So Iron Man is just a Commoner. The Fighter wins.
I admit, it's been a hot minute since I've watched Iron Man, but to accept that this is a relevant analogy, I have to assume that Iron Man must have haphazardly collected random bits and bobs that all happened to work together without any outside manipulation to make him a superhero.
That's the thesis for Iron Man right? Unbelievably lucky scrounger?
In addition to being a false comparison, it's also beside the point, which was how powerful should fighters be?
If your answer is "well, with this specific gear, they can do x" you are answering a question, but unless you are contending that the gear in question should be assumed (with sufficient reliability to build it into the class mechanics), then you're answer is missing something.
That something is "how powerful should the fighter be without the gear?"
The comparison question has been asked twice already and been avoided twice. Setting HP the same, how much more capable is a high level fighter than a level 5 or level 11 fighter? Does the magnitude of this incremental capability make sense?