As others said, training wont fix stupid.
An example, not long ago the "range officer", the guy in charge of training the towns cops, was supposedly working on one of the department's service pistols. He pulled the empty mag out of the gun and laid it on the table, then for some unknown reason, took the full mag out of his gun and laid it on the table.
After he finished what he was doing, He put the "Wrong Magazine" in the "fixed" gun, and let the slide go forward, and the gun discharged through the wall into the break room (where my stepdaughter was).
With all his training to become a LEO FI, stupid still kicked in. He was batting 100, violated 4 out of 4 of the safety rules.
(and people ask why I go out of state to do my yearly LEOSA qualification).
Mandatory training wont fix this. But it will open up Pandora's box.
I'm not against training, not by a long shot, I'm against government mandatory training.
Who is going to set the standards? will they change every time someone does something stupid? Will it change when politicians change? What will it cost? Will it prevent low income people from being able to exercise their rights? Will it make shooting sports a rich man's sport?
Kind of like gun control, never ending, when a law fails to prevent crime, instead of getting rid of the law, they all more laws, which still don't work.
Same with mandatory training, you set the standards, someone does something stupid, you raise the standards. This goes on until no one can pass the training.