so you asked this question to post all the answers yourself, rightI am well aware of firemouth aggression but in my experience when I did have the aggressive cichlids, the firemouth would be the one who would be the so called punching bag. My male marbled angel is actually the one doing the chasing. He chases the firemouth all over the tank,
I don't know in what world angelfish are classified as "aggressive cichlids", but you'll figure out whether it works.