Yes, certain species of fish don’t do well in my tank and tend to be susceptible to the same decease symptoms. He is slightly over a year old, grew rapidly to 8 inch, and hasnt yet reached his full grown size. Several of my former GTs reached 10+ inch and died in older age with the same symptoms. There is possibility that the same pathogen caused different symptoms in different fish, for example, my Africans tend to die from bloat, not HITH or lip swelling.
I don’t know what the grand old age of GT can be if kept in a low density clean environment. I kept many GT in the past in a crowded community tank and their average age is between 5 to 7 years, typical life span of medium size cichlid. But since I lost my old GT 3 years ago, my tank is cursed with the same decease symptoms hitting every young GT and killing them before they reached full size.
African cichlid come in all temperament, and not all are murderous. The most peaceful cichlid in my community tank is a frontosa, and groups of Julidochromis, Lamprologus tretocephalus, and Hemichromis exul. The most aggressive Africans are MBUNA, and Victoria cichlid, less so with Malawian Haplochromine. Lake Tanganyikan is a mixed bag with the most and least aggressive species.