I tried keeping a tri of comps with the rest of my haps a while back... Ended up trading them in at about 7" because my show-quality male A. baenschi lost an eye in a fight, and so did one of my female C. borleyi... Plus they kept all of my other fish hiding in the corners when it came to breeding. They are mean, but they are definately beautiful fish! (Makes me want 'em back! LOL) Their aggression shouldn't be a problem with the N. livingstoni though...