What information can I read to reinforce that statement and learn how to properly stock the tank? The information I read was that all cichlids should be added at an earlier age while they are small and grow together rather than adding further cichlids later once one has grown as they are unlikely to survive up against an aggressive fully grown Cichlid like an Oscar.
Also I have not seen anything that states that a 110 G tank is maxed once you have a single Oscar and a smaller fish, but as mentioned I am new at this so it is very possible I am reading the wrong material here. My intentions weren't to overstock the tank like it was a SA tank but to stock it to the max that 110 G would carry once everything is fully grown.