So, we want to model disabilities that we expect won't really be an issue, because the heroes overcome them anyway?
I twisted my ankle, so I have a limp - but, when it really counts, I push past that and can get the job done. If someone came up to me and tried to kill me, it'd be a bit easier than if I were whole, but otherwise it doesn't actually stop me when the chips are down...
There's a desire to put in modifiers, sure. But, if, when all is said and done, we expect (and thus design the system so that) the hero *will* overcome those modifiers, why are we putting them in at all?