User blog comment:Gundam Legilis/Extracurricular In Depth - The characters/@comment-11188061-20140901044855/@comment-3146930-20140901065835

She only has three people currently at Beacon, but she has an army of White Fang goons at the ready armed with military grade weaponry. If that thing she is holding is in fact a needle (I thought it was a hair at first) that can disrupt a person's Aura and/or Semblance, then it wouldn't be that hard to have members of a group trained in stealth missions to sneak in at night and take out the school's top threats.

The real issue however is more the limitations of the show itself. Obviously the freshman are the main characters, but we really haven't seen any upperclassmen of any kind. It also doesn't make sense that Cinder is targeting freshman, unless they are extremely skilled like Pyrrha. Glynda as well is the only teacher we have seen outside of a classroom and is also the only teacher that seems like a threat to Cinder's plan. Obviously those participating in the tournament would be the more obvious targets, but if Cinder is making a list of threats then it wouldn't just be limited to those in the tournament; especially considering how smart Cinder appears to be. She isn't sloppy and doesn't appear to leave things to chance.

It also may not be as hard as you think to take out the main threats. First off we don't know how any students are actually at Beacon or any school really. Ozpin had enough chess pieces out for 40 new students total, so hypothetically the school may only have a small population of students (anywhere from 150-300 probably). We also know that teams like CFVY are sent out on missions away from the school, meaning even less students are there. The school appears to have a limited staff and no type of security officers anywhere. Even with exchange students coming in from other schools, I can't imagine there are that many.

In reality, Cinder should just hack into the school's records and take out the students with the highest grades currently or those with the highest marks on Ozpin's rigorous entrance exam. However this is all assuming she actually has a weapon that disrupts Aura/Semblance and wasn't just speaking metaphorically.