A case in point;
DW has a cousin, widow type, who gets squired around by a retired FBI type.
One night after dinner, they are walking out of the restaurant when the FBI type stops so suddenly that she bumps into him. He scans the parking lot and says, we are going out through the kitchen, which they did. And by a circuitous route they got to their car, drive out and then he makes a call on the car phone. (Before cellphones were common) "Who has a stakeout at XXX? Nobody? Well, somebody does, maybe you ought to look into it."
Next day, item in the paper, three men arrested, one armed, in the parking lot. What were they doing there? Didn't say.
She asked the FBI type. Turns out he always scans parking lots before he walks into them. He spots all three men, located in places where he would have located if he had a stakeout going. If they had been in a group, he might not thought much of it, but they were spread out.
His opinion? Carjackers. You go to your car and one of them is close enough to engage you in a conversation if he is not the gunsel until the gunsel comes up. If he is the gunsel, well, you all get in the car and go for a ride. If you are lucky, they drop you somewhere..if you are lucky.
Why would three in a group not alarm him?
Well, odds are that if a group started walking towards you, you'd get alarmed. In fact, if just one started towards you from a group, you'd watch closely. But if the guy was already near your auto, and seemed to have no connection with the others,......
But then it is possible that three in a group is a bunch of amatuers....up to evil deeds too.
You have to play the odds.