I understand what you're trying to say, but as far as aggression goes, the titan, queen, and undulate trigger in their adult size and disposition can pretty much destroy any other marine fish that people can keep. However, of those three, I would rank them this way in terms of aggression :
1. Titan
2. Undulate
3. Queen
Each fish has it's own personality, though. People have claimed to keep clown triggers in reef tanks for years with no ill effects, and to keep other aggressive fish in community tanks with no bad results. However, as a rule, I think the aggression chart would stand with those three in that ranking.
Has anyone ever done this experiment to see who would win out? It would be pretty expensive and cruel, but isn't that usually what scientific experimentation means?
Peace,
Chip