This is like catching your wife in bed with another man and asking "what other men have you slept with today"?
Does it matter? One crime is enough!
Looking at it another way, how many crimes do *YOU* think must be committed before action is taken? What is the minimum threshold number of crimes? I thought it was one, but apparently you feel differently.
If the shoe's on the other foot - if you're aggressively confronted on a public street by two guys who aren't the same color as you, and who have a grudge against you, and you can clearly see that one of them has a shotgun - isn't it reasonable to conclude that you're about to die and that your only slim chance is to get in close with the guy with the shotgun and make as close to a fair fight of it as you can?
No. It's reasonable to conclude that if you attack the one holding the shotgun you will definitely die.
Your admission that Mr. Arbery was aggressively confronted under a direct and absolute threat against his life is now on record. Over swiping a clawhammer, and snooping around on a construction site. Oh, and for stealing a handgun at some point in the past, not today.
One crime is enough to get arrested, although I personally believe if you called the cops on some guy snooping around on a construction site they'd actually be a little bit miffed at you for wasting their time.
To get killed over takes a certain sort of crime, involving the life or personal safety of another human being, none of which have happened in this situation except the McMichaels escalating the situation and confronting Arbery aggressively, directly, and under a clear threat to his life, as you yourself admitted.