In a street mugging, may one reasonably assume they will be gravely injured or killed? That depends on the history of muggings in that area, and the demeanor of the BG(s). Every situation is different.
I see contradictions within the above statements.
The contradiction is that the above post claims defending yourself in a "street mugging" depends on the history of similar incidents in that area, but then says every situation is different.
I submit that each incident is unique. You are not responsible for knowing the outcome of similar incidents in any area. Your actions will be judged based on the incident in which you are involved.
First: Being "mugged" and being "robbed" are semantically equivalent. In either case, another person uses threats of violence or great bodily harm, including death, to obtain valuables from you.
Any time you are approached by one or more persons who demand you turn over some valuable(s) to them there is an implied threat to your safety. If any kind of weapon, including clenched fists, are displayed, there is the threat it will be used. If you're alone and facing two or more persons who have moved to flank or surround you, the implied threat is a severe gang-beating.
Secondly, a robbery
is a life-threatening event. The robber uses the threat of force that says "look here, if you don't give me what I want, I will hurt you or kill you."
A friend was "mugged" not long ago and because she hesitated in turning over her wallet, the unarmed perp attacked, giving her a vicious beating that broke her cheekbone, shattered the orbit of one eye and gave her a skull fracture. Eleven days in the hospital after surgery. When he was caught, he said "I shoulda made sure the b---- was dead."
As far as the OP is concerned, in any state where CCW is allowed, if I were carrying, the appearance of a weapon being passed would have resulted in (at a minimum) drawing my weapon on the thieves. Depending upon their general demeanor during the event it could have involved loud noises as well.
Final thought:
The "experts" tell use to give a robber what he wants. The problem is,
what if he decides he wants my life?