Much of this seems to me like word play and syntax.
The guy who can't walk, he's at a disadvantage to those who can walk, I wouldn't think it's wrong for him to obtain a wheelchair or walking aids to help himself achieve what he wishes.
Same for mental health. I'm ADD and as much as I hate to admit it it does make achieving what I want to harder than the average person, I don't feel slighted in the least by being diagnosed with it and given access to a means of helping myself.
We all use tools to improve our abilities in things, calculators, computers, knives all sorts. I suppose it's more the stigma around the tools you need to keep up that's more the issue.
Although you do run into disturbing hypothetical situations eg.
If [culturally disempowered group] changes say, their physical appearance to appear more like [culturally empowered group] they will be able to achieve there goals easier.
Maybe what I'm thinking is more ability, if you understand what I'm getting at and I haven't completely missed the point