I like how you connect Cerberus and intimidation. From how the story went, he was but a tool used to enforce Hade’s rule or intimidate someone, therefore, he is neither good nor evil. I would compare him to a gun, for it could either be used to enforce and defend or intimidate and kill.
His appearance may seem monstrous, but I think the characters that use him are the “other”. Hades, who uses him to enforce his rule within his domain, and Jason, who used him to intimidate the king into releasing Hercules.
I think the same concept goes with police uniforms. The uniform has taken on a negative connotation due to the injustice conducted by the few that wear them. Unfortunately, some of this injustice go unpunished which give people the