No, I am not wrong. I can't even imagine why you would say something so foolish.
THEY were the aggressors, not Arbery. They went after him and he was trying to get away. Put yourself in the situation:
You're jogging along and three guys start yelling at you and chasing you.
You run from them.
They get in a truck and come after you.
They catch you and hold a gun on you.
You try to take the gun from them and they shoot you dead.
Were they just acting in self-defense?
I can't explain it any simpler than that, so anyone who still wants to believe that these yahoos were acting in self-defense it's exactly that - they WANT to believe it. And they're wrong.