I have 8 Juvies left right now and i have kept this species for several years, yes they are Carnivores and need a higher protein diet, do not treat these as Herbivores with a Herbivore diet, i know you didnt state that they were Herbivores but the Omnivores route is where some hobbyist get their feedings wrong, A high protein pellet and flake will fit them well.. Yes they are aggressive towards conspefics but i have kept them with a wide range of Tangs in the past like Julidochromis, Brichardi's and Altolamps.. A minimum tank size for a pair species setup would be a 40 breeder with a 55gal being better.. I put 5 adults in a 50 breeder for a couple of days as a temporary site until their tank was ready and they harassed one of them to jump out of the tank..
I have had a few sites contacting me on my approval of using my Tret photos for their site and to write an species profile for them.. Your right there is not enough information on them.. they attain a size of 6" their name is Neolamprologus Tretocephalus common name is Poor mans frontosa, they are a substrate spawner, carnivore..