I'll be honest, I've been recently believing that CoH is actually better than Jaw by a decent amount. Her SA1 is pretty awful to be honest, but her SA2 is fantastic and lets her do absurd damage that's either comparable or superior to Jaw. Like ZeoW said technically Jaw scales infinitely, but that scaling is very conditional and in a normal match the most you'll likely see while maintaining chaos is 60% (Surgeon buffs + Final Stand). On top of that, Jaw's SA actually doesn't get boosted by move stats while CoH does, so the damage difference is very noticeable. The cherry on top is starting green; with water being a top tier defensive element having an effortless Chaos to slide on her is powerful (to the point that diamond Nunsense is honestly quite reasonable). Dark meanwhile has a foot in the grave, with RE being the only real great option and everything else being a gimmick at best.
There is one thing that technically holds CoH back: proof. In theory I think she's far better, but as I don't have one to play with and most people who use Jaw don't use CoH as they do the same thing so similarly that it's not worth 5m coins to upgrade. People don't see CoH sweeping teams while Jaw is a tried and true option. I hope one day to get CoH and show her off, but until then, I'll have to admit that much lol
As far as inconsistencies, fighter toolkits are extremely important. I'd consider being a Parasoul an instant boost to any SA thanks to her incredible toolkit, while being a Band is borderline a competitive death sentence thanks to his lack of doing anything but stun (which is a bit too nerfed to rely on tbh)