Dr. Strangemonkey said:
I like this one. Particularly since if you keep the actual feats within a broad range of masteries unarmed combat becomes a good secondary strategy with characters, which is the way it works out in a lot of the literature.
That way a guy who just does unarmed combat is still great, but a guy who specializes in wacking people with clubs might actually have a good side specialty in defensive martial arts, grappling attacks, or using his fists as a light weapon.
If you really wanted to build up that modular component you could also have minor feat chains and major ones. Say basic defense, attack, and grapple chains capping out at five or four, and then really exotic chains begining at no lower than four and that's where'd you'd put anti DR chains, leaping attack chains, pressure point stuff, and (if you really wanted to go hardcore) stuff like flaming fists and chi-beams.