Hmm good topic.. I already have a big CBS and was wanting to add peppermints. Funny you say the peppermint is aggressive LOL
I always thought they would be sorta happy and pepperminty relative to the crabby ol CBS. I think I will try to add some now and keep eye on them.
We do have a blood red fire shrimp (closer in species to the peppermint) in Jeanenes SW
tank and that thing will just about jump onto your hand and start cleaning it. It will also chase the fish around wanting to clean them. Conversely, our CBS will jump a mile if lil plant brushes him. The CBS acts mildly paranoid and reminds me of inspector Clouseau when he thinks Kato is going to ambush him. He carries his claws like he is going to pull a karate move. HiiiiYAA!! LOL