Simply not going to happen. It will create more problems than it solves.
Scenario one.
The bit between the flight crew walking off an aircraft, all carrying guns, and arriving at the armoury. Not too difficult for some airport working n`er do wells to club them over the head and nick their guns. If you believe all airport workers are safe to trust you really are supping too much of the old sauce.
There you go a couple of guns on the wrong side of security. Give them to numb nuts terrorist who is em planing. By the time the knocked out pilots are discovered many aircraft are already in the air, which one is it? Result major terrorist incident caused by arming pilots.
It really is more trouble than it is worth.
As for training pilots to a lesser level than police/military. The Police and military that have firearms and are correctly trained, regularly have accidents, which kill one of their colleagues. Pilots will be no different.
As for the Odds Wino I hereby accept your payment of 100 bucks.
However you won`t have to pay it because pilots on commercial jets will NEVER be armed so it is a moot point really.