There were two actually.
The first how many armed guards would be needed to ensure a school is safe? Are we suggesting one per school or one per classroom?
The other is at what point would an armed guard deem a student to be a threat?
If they bring a weapon onto campus?
If they draw a weapon campus?
Or after they shoot a weapon on campus?
Some more questions,
What legal powers do these security guards have? What level of training?
What level of weapons do they need? If citizens can get hold of assault weapons and body armour do the guards need likewise?
Are they expected to defend against assault weapons with a .9mm pistol?
Do we want armed government police patrolling our schools?
What implications would it have for freedom in schools?
What avenues for abuse of power does this open?
As you can see from my questions you will be unsurprised to see i'm not warm to the idea. I think the concept of putting more guns in the hands of the "good guys" creates issues however well intentioned.
Therefore I look to see how can we get weapons out of the hands of the bad guys.
I can't understand your question.