I've been bouncing around a 4E campaign idea for a while, and I like where it is going. I know that I want a few non-PHB races (plus humans) as PC-selectable. As such, I'm looking to try and create/co-opt them from smart people at EnWorld 
Fluff-wise, I am leaning toward Human, Minotaur, Lizardfolk, Stonefolk (placeholder names). While the Human race is versatile as far as classes go, I want to design the other 3 to overlap somewhat as far as reasonable class options. I don't want Minotaurs to be the obvious and only "fighter race". I think multiple options allows for more interesting backstories.
It's here that I'm stumped. I don't know how to go about this in a way that doesn't over/underpower the races. How have others gone about this?

Fluff-wise, I am leaning toward Human, Minotaur, Lizardfolk, Stonefolk (placeholder names). While the Human race is versatile as far as classes go, I want to design the other 3 to overlap somewhat as far as reasonable class options. I don't want Minotaurs to be the obvious and only "fighter race". I think multiple options allows for more interesting backstories.
It's here that I'm stumped. I don't know how to go about this in a way that doesn't over/underpower the races. How have others gone about this?