Nice information on force continuum and the levels of weapons employment.
The down side of these weapons is the ABILITY to Deploy them when needed.
I have written before on my carry of weapons and the failure in instantaneous situations to be able to get to and deploy my weapons.
Most weapons mentioned on the clip
OC spray
ASP
Knife
Pistol
In most areas they must be concealed,that means you must get them out from where ever they are ,and ready them for use.
The rule of 21 feet,no matter what you think of it,shows that a Police officer with a pistol in the holster at 21 feet cannot,if standing in a stationary position, pull and fire that weapon and hit a person charging at them with a knife who covers that 21 feet in approx. 1.4 seconds on average before being stabbed.
If we apply that distance of 21 feet,which is far ,for an altercation,one WILL NOT be able to see the threat,identify it,search for and draw the weapon before the threat is on you.
If you see and identify a threat at 21 feet or more,then get the heck out before you get closer.
As I found ,even with massive training to deploy a weapon,when the crap hits the fan close in to you 9 feet or less ,good luck deploying and using you weapon of choice as listed on the clip.
You had BETER KNOW how to use your empty hands ,or travel around with your weapon in your pocket ,in your hand ,at ALL times.
my opinion.