Yes they can be quite aggressive, especially once a pair forms they tend to kill off everything else.
I've seen SOME have luck with tankates who don't compete for food or hiding and stay out of the way basically dither types. But in my experience anything that get's into their caves, dares to challenge them or competes for food will be killed off.
Even those perfect dither tank mates only work sometimes, and when they do they will still get killed from time to time. Another thing to consider is that if breeding occurs everything else will be killed right away.
Sort answer, this species is best kept solo, if your lucky enough to have a pair who get along you've already got more tank mates then most people get away with lol.