If you want to drive a nail, do you use a tire iron, or a hammer?
Differences with a gun, people feel bolder in pushing a confrontation. Assault is physically easier. It takes all the need for agility and grappling out of the confrontation. A gun wound has five times the morality rate of a knife wound, plus a wound with a bullet in a vital organ is many times more deadly than a knife. (Scientific American). So, more confrontations that would have ended with assaults instead end with homicide.
It would be nice to know how many homicides would have still occurred if the right tool hadn't been available. Unfortunately, we don't have that stat. You can, however, compare countries rate of assaults/homicides with one another, then find out how many assaults resulted in homicide. You could also compare the rate of "hot-headed" assaults between countries with and without guns, where every weapon is available but guns, and see which country consistently has the higher rate. Then you would get the idea 1) if guns are emboldening people into confrontations, and 2) if the assaults from those confrontations are leading to higher homicides.
So, if the answer to both of those were yes, would that at all change your mind?
I'll add also, statistically speaking, guns don't protect you. People who have a gun in their household are actually twice as likely to die of a gunshot wound than those who don't. That's considering accidents and suicides (which are also easier with a gun and make more difficult options moot).
Would they have died if they had knife or bug poison? Not when they're twice as likely.