Jester David
Hero
You can’t.And how do you balance that over the course of only two rounds? This edition isn't the sort of tactical combat game where you can spend resources and still have time to recover them later before using them again in the same combat.
This kind of design would have been great for 4th Edition, where a certain number of rounds were built into the game and tactical combat was the norm. It would have been easy and interesting to have a certain number of “rage points” needed for a fighter to use his Daily powers.
It’s harder in D&D5, as that edition is balanced around the adventuring day and not the encounter. There’s few assumptions made regarding individual encounters. And we don’t know how many short rests they’re expecting to have during an adventuring day, if there’s any assumptions.
However, a resource could be based around the adventuring day, where the character slowly gains “fury” or “adrenaline” until the expend a power or take a short rest. So they get more powerful as they adventure without a break. You could certainly build a fighter subclass around that idea.
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Non-magical resources can work, but they should generally make sense in the narrative. Fighters don’t have innate magic and thus shouldn’t have any powers that replicate the mechanical effects of magic (unless said power is designed to mimic something a fighter can do).
If they can only do something once per short rest there should be a reason. If they can only make two Super Attacks per day before getting “tired” but they know two different Super Attacks, it’s odd that they can only perform each once rather than choosing which arrangement of SA to perform.