On the Black guy:
He fought with a man who had a shotgun and 2 other guys for backup. I understand his anger at being chased and held at gunpoint but I would not have fought with them, I don’t think, but he made his choice. I wasn’t there.
Very well put. He could have justifiably been afraid for his life. Thinking he was about to get shot, he played the only card he had and fought back.
Correct, neither you or I were there.
The other side of the argument you're making is "fight or flight" when fear takes over. It's reasonable IMO to assume that Arbery believed his life was in danger and "fight" took over.
I think if you polled FR, it'd be fairly split down the middle of who'd fight and who'd run in a case where three people have confronted/cornered you and one has a gun.
According to a story in the DM, Arbery was diagnosed with Schizoaffective Disorder after a confrontation with his mother where he refused to let go of her car keys. And, again according to that story, trace amounts of THC were found in his blood. If true, may or may not have had anything to do with his reaction.
That said, it looks like the jury made the right decision.