CW's b3 is kind of better defensively since it has a low hitbox and moves her really well but shes immediately next to the opponent and at negative, so its like a mid hitting KF slide.
NW b3 hits mid, and you are at plus, and if it whiffs you're not next to the opponent which helps create space. IMO in this game move range is greater than frame data.
For example, Supes breath creating pushback makes his f23 hit, but not the defender's reversal d1s and the like. Zatanna's 221 is + but there is a lot of pushback which makes it weird to really follow it up with anything outside of cards or divekick.