Hmmm... so at the generation of Yoko/Alita Panzer Kunst started to become this bloodthirst... pretty clear Yoko's last mission was just the tip of the iceberg for the fall of PK.
Yoko's true strength is that she doesn't conform very well to normal methods, as an adult, her edge comes and goes... but with all the trauma and shit she deals with, it is understandable... but when she enters her zone... you will need to be a top-level fighter to have a chance, and with that, I am not saying the opponents need to be just good fighters... they will need to be creative and smart, Alita has dispositions that make her a pain in the ass in the best of cases to deal.
Erica's face on page 19... it seems she didn't change a few parts of her "bad habits"... as they enter puberty, I can see that what led Yoko to kill her was a pretty big betrayal... can't even say it wasn't deserved either.
At this point, Erica is a child full of traumas and pain, her "bad habits" are understandable... but at some point, especially in the present time, her actions can't be chalked up to trauma anymore.