The Mauser school was the one that specialized in hidden weapons, using bullets in unorthodox ways and explosives... I have to admit, Huizenga's design caught me by surprise... but now that I connected the dots, he is VERY appropriate for that school.
Same for Schreier... she looks more like a supermodel... but when I consider she is from the Medoruma school, which seems to be the master of oscillation arts, she makes sense... during the time oscillation attacks were something like an "exotic" art.
Panzer Kunst was one of the first martial arts to be made to adapt to zero-g fights and the use of cyborg bodies and what they allowed a fighter to do, but if I caught the hints well... oscillatory attacks in this time were at its infancy, even in the present time it feels like they aren't well known, mostly because the destruction of the Grunthal and how much that type of skill was connected to them.
I would say too that, because how easy electromagnetic acceleration became to do with cyborg bodies, and the existence of Electromagnetic Karate, the popularity of oscillation arts declined, because as powerful as they are... they can be "slow" and demand a lot of skill to be used well... not that electromagnetic arts are weaker or don't have subtlety to them, quite the contrary, but their intro level is easier, so the scrubs latched to it more.