Arbery reacted reasonably. Instinct says fight or flight. Bunch of guys, some in pickup trucks with shotguns or whatever, chasing him down, he's going into flight mode. That makes sense. And once they are both too close for being able to run without being shot and they are also somewhat surrounding him, he's cornered, in which case to survive, he's got to switch to fight mode. And that means subdue and/or take opponent's weapon, then reassess the situation, to either shoot the chasers or run again.
One thing that could have changed the game is if some of these entitled lunatics yelled, "we're making a citizen's arrest! Stop running. We are arresting you." OR if they had called the police and let the police handle it, provided they didn't lie and say Arbery was armed or dangerous, in which case, that could also end up in his death.