No, because they get drunk or irrational over some perceived slight and pull a weapon on whomever they see as the problem. They also get bored and do stupid things like playing quick draw, until one weapon accidentally fires.
Witnessed all of that in the early 70s when I lived in the barracks and fortunately nobody killed but some close calls. These were upstanding and dedicated Marines by day but when liberty and alcohol called some were less than intelligent.
I think they should be able to carry and to have access to automatic weapons in some situations and areas. I don’t think that it would have stopped the shooting out of the blue from a car at the recruiting station but it might have saved some lives at the training center. If nothing else, it might give the shooter some pause before trying. As far as access to grenades; NO, I knew too many who would not throw it correctly, personally witnessed one drop a grenade in the throwing pit and was saved by the instructor who was amazing fast in pulling him over the barrier.
The instructions regarding the Holy Hand Grenade of Antioch come to mind.
If you are on duty you should be armed. As Sgt. of the Guard of the Ammo Dump at Camp Lejeune back in the early 80’s I was armed at all times on duty as well as my man.