What archetypes? I've explained before - if a given concept is something you could see in a heroic fantasy story, it should be doable. By the way, want to know what sort of character can't work in core 3rd edition? Drizzt. Also his arch-rival Artemis Entreri. Their combat stats in the FRCS book are rather telling.
As to how much crunch - not very much. D&D Next has already made dexterity-focused fighters more viable by something as painfully simple as extending the list of weapons you can use with finesse, and letting them be used this way without a feat. Suddenly, Drizzt with his twin scimitars, high Dexterity and average Strength is no longer going to scratch ineffectually at anything roughly equal to him in level. Other options that are lousy in 3rd edition can be brought to at least the baseline level of usefulness with similar changes, if only the designers want it. The best way to make various combat styles cool and useful would be to make unique manuevers that are used with particular weapons and methods of fighting, though.