I had to remove two peppermint shrimp from my display because they were eating bot my rbtas. They were model citizens for almost 6 months and then one day I caught them eating a hole through my starfish. I removed the starfish as it was obviously dead and over the next week they ripped half the flesh from my plate coral, tore tentacles from my frogspawn, and nearly killed both of my rainbow btas. I think it depends on the shrimp honestly. They mowed down my aptasia problem but eventually took a liking to all of my fleshy coral and inverts.