In my opinion, you could not rate the aggression of a wrasse on a list as you could with a trigger. Wrasses all have different personalities, whereas a trigger is usually a trigger, with few exceptions. The one thing you can bet on is that fairy wrasses are the least aggressive. However, you can usually count on most Thalassoma wrasses, such as the lunare, to be a very greedy eater and get more and more aggressive as he gets older because they demand swimming room and territory. It's just too hard to say what wrasse is more aggressive than another. It all depends on how they are raised. Many people have aggressive six line wrasses that kill their other fish, but then other times, they are never a problem.