in order for a fighting game character to be well-designed, there needs to be appropriate weaknesses to counteract what they do well. Black Canary, in exchange for her great damage, mix-ups and general dirt, is unsafe, doesn't have much range, and has a hard time against zoners. She is a well-designed character.
This is the problem with the upper tiers in Injustice 2 (I won't go into other games), they don't seem to have any weaknesses, or the ones they do have don't hurt them much. Aquaman, a character who was designed around defense and keeping an opponent out, could also hit for 400+ with 1 meter. He could hit you for (300+?) midscreen 1 bar and 250ish fullscreen 1 bar. He was a poorly designed character. Deadshot, a character designed around projectiles and zoning, also had safe, up close options for doing damage, effectively making it pointless to play any other projectile based character. He was a poorly designed character.
So with that said, what weaknesses to Supergirl and Catwoman have?