Armed security guards. What a range you find in that field. Wanna be cops, guys who just love the gun and the uniform, psychos, people who should never wear guns, and yes real professionals.
Most criminals who plan to hit an armed guard not only plan what route, when and where, but which crew to hit.
Most armed guards have not really caught on that the gun is not there to stop the professional. The professional will have it planned out. You will look up or turn a corner only to yourself looking into one or more guns. There will be no time to respond. But many bull**** themselves and dream of exchanging those rounds with the bad guys. The guns are really there to scare off the amateurs who see a bag of money and think "what if" then they see the gun.
The real professional armed guards try to handle themselves in a manner than the professional criminal chooses another crew to hit, and amateurs don't even dream about it. They "beat the intent". (Many are placed in circumstances beyond their control.)
I remember one time I was reloading a cash machine placed in the brilliant location of a Seven Eleven where to work on it the vault had to be opened right out into the store. I looked up to find my "guard" reading a magazine at the book rack. I closed and lock the vault and asked him what the &*^% he thought he was doing. He commented that if someone wanted to rob us there was nothing we could do to stop them, so why try. I explained that he was there to scare off the amateurs and that professionals pick the crew they want to hit. I also clearly explained to him that if he didn't put the magazine down I was going to shoot him myself.