In Apocalypse World as such, the stats aren't on equal footing. It's slanted, like. If you're water, you flow away from cool, toward weird. Being cool requires effort and dedication, and becoming more weird is kind of the inevitable way of things.
"Becoming more weird" means three things. (1) Getting weirder, like going from weird+1 to weird+2. (2) Using weird for more basic moves, like getting Unnatural Lust Transfixion or Seeing Souls. (3) Getting brand new things you can do with weird, like Frenzy or Bonefeel. In all three of those ways, getting weirder is easier than getting cooler.
Hard is second place to weird.
So what happens with the Apocalypse World playbooks is that the ones that emphasize weird, like the brainer, have lots of weird moves and are kind of overwhelmingly pro-weird, and same thing with the ones that emphasize hard. The battlebabe, though, emphasizing cool, has relatively many sharp, hot and weird moves, and relatively few cool moves.
Whether a similar stat slant should exist in your game, I don't know. That's up to you! But that's what's going on in Apocalypse World.