Heros sp Rotkiel stay smaller than uaru.Heros get about the same size as uarus
I agree in a large enough tank they work well with many cichlids.I've kept a school of around 6 silver dollars with all kinds of simi-aggressive Cichlids with great luck , Oscars, synspilim, red devil, black belts, Chocolate cichlids, sevrem , etc in a 135 & a 210 gal
Yeah tank size plays a part but also some fish are just natural born killersI've tried a jack Dempsey and he killed 3 silver dollars, that put me off aggressive fish, I thought about an Oscar but I think the tank would be too small or over stocked.the only fish I would try would be a chocolate cichlid or Oscar .