Hellenistic art does show empathy for their enemies. Interesting that they felt admiration and empathy for the Gauls, because after Greece was taken over by the Romans, Rome fell to the Gauls. The Romans barely put up a fight, not even posting sentries outside the city walls. Important Roman citizens such as virgin cults and politicians fled to other cities, while the elderly were left behind to die. Previous to the sacking of Rome, the Roman empire was suffering an economic slump – perhaps because of expanding the empire too quickly by taking in Greece. I read somewhere, but can’t find it again, that Rome was so undefended because they couldn’t afford to pay their soldiers. Anyway, don’t feel empathy for barbarians.
Later Rome fell again to the German Visigoths, more barbarians.