I have a 65 display and have been thinking about an upgrade when I eventually move. I've seen plenty of videos of larger tanks with species I'd be wary of adding to my own tank due to their supposed aggression or PITA status. I'm thinking the likes of damsels and dottybacks, for example, or fish species where one is fine, but multiples cause issues. People seem to report no issues with them in larger tanks, but in a smaller tank the likes of dottybacks and damsels can wreak havoc. While nothing in this hobby is as simple as "X is the line where the issues stop," what's a rule of thumb that would make these species, or others generally, most likely to not be such pains? It would help a lot as I try to plan a potential new build