My issue is with this perceived need for modularity. Is it really necessary or beneficial to distinguish between, "I'm the FAST climber!" and "I'm the CAREFUL climber!" in a roleplaying game?
To turn this back on you, "Maybe?"
I recall playing in an
Ars Magica game many, many moons ago, and one of the things I recall doing was picking what I recall to be something like D&D 3.X-ish feats.
One of the guys I was playing with picked some ability that helped him cast more or better spells of a certain kind; I can't recall which. He was, though, choosing to make his character the "Fast Climber."
Me, on the other hand, I picked the "Flawless Magic" perk / feat / ability. It's benefit was, essentially, that I could never botch a spellcasting roll - I would always achieve at least the minimum success. I made my character into the "Careful Climber" of the group.
We each played differently enough, even in a relatively short campaign, that the differences between being the fast climber and the careful climber were borne out. And if you can do it in one aspect of one system, why not another?
I'm not saying that the specific examples are exactly the best, but I don't think Mike's saying that, either.