^I mentioned nothing about the berimbolo.
I disagree with your post. Though it may be lost in translation. You are in Mexico.
I am saying a person that robs you armed is a whole different person than someone who burglarizes. By them robbing you armed they are willing to hurt another person to get their demands, and know that they could be severely hurt or killed in the process by their victims, or police.
I am an east european, who lived in Japan, China and Mexico for the last 15 years.
I was a teenager when the Eastern Bloc crumbled and witnessed and experienced first hand many of the hypothetical scenarios you are picturing here.
I personaly know people from both sides of the law, various military servants (US marines included) and I am describing what I have seen and what those people have told me.
The guy who comes at you and shows you a weapon, doesnt want to hurt you. He wants to take your money, wallet, watch. If you start screaming and defending your self, you might get hurt, because he will panick. If you just hand him over what he wants, he will flee asap. The thief is not a killer and he is as scared as is his victim.
Robbers and burglars are concerned about their identity been revealed, so avoiding eye contact would keep you safer.
People who want to hurt you, are different. They are predators, who operate on known territory and most important THEY HAVE MOTIVE! They are not after your riches. They rarely will hang around good neighborhoods and if not familiar with the behaviour of this type of criminals, you will not see them coming at all, until its too late.
You are assuming that everyone on the street is eager to hurt and kill people, when in reality it takes a special type of mind (or drugs) to even want to do that.
Talk to your local police officer and you will hear this: in case you are robbed at gun or knife point, just part with your belongings and the attacker will most probably leave. If you are getting kidnapped though, fight till the end. So, if anyone points a gun at you and asks you to follow him in the alley/ the van, away from other people or possible help, do your best not to.
The berimbolo was an example to people who believe sport oriented art can actually prevent this kind of dangers.