I'll just note that having provoked that reaction from several people, I've failed a little in my intent. I was deliberately going for things that aren't so tied to ability scores--the idea being that "prowess" implies certainly some strong physical strength, dexterity, and constitution, and isn't entirely unhelped by a touch of intelligence, wisdom, or charisma, either. Cunning is as much about fooling people as knowing what to do or how to do it. Arcane is about knowing strange stuff--whether used by Dex to mix odd potions or Con to withstand the terrible pull of some body draining process or Int to puzzle out how to make it work. And so forth. Sometimes the very last thing about dealing with the supernatural will be "wisdom"--albeit that will be more true of evil cultists of some alien power than the PCs.
You might think of these as more replacement power sources (in the 4E sense) than anything else. That's not exactly right, either, though. Thus calling them "idioms".
With idioms, look at the three "pillars", combat, exploration, and interaction, and ask how a character built on that idiom is going to handle it. A character built primarily on prowess faced with an interaction challenge might use intimidate (almost brute force, sort of based on Str) but might also, in some contexts, resort to taking the princess out on the dance floor. He is no great talker, but he "sweeps her off her feet" with his grace and poise.
If I had done a better job at teasing out my meaning, then the idioms would have more obviously and naturally crossed pillars and ability scores, instead of prompting the reaction I got. That said, this is all brainstorming. So don't let the above discourage you from running with it anywhere you want. My idea was not the intention of the several people who prompted it, either.
But I did want to state this in case anyone had some thoughts on running with it the way I originally intended, too.
