I hate to say it, but I've had better luck recently just floating the fish to temp acclimate and releasing them into the tank with the lights off. If I really thing about it, I'm not sure if fish are really able to acclimate themselves to varying water parameters in a matter of a few hours.....based on what I know about physiology this in reality takes more like a few days. The stress of "acclimation" may be more than its worth....maybe I'm completely wrong but I have been thinking about and experimenting with this lately.
FYI, the worst fish to fish aggression I have ever seen is when I made the mistake of putting a McCosker's wrasse into my first reef tank with an established six line wrasse. The McCoskers fell victim to the sixline's repeated ballistic missile-like attacks and before I could get my net he was permanently brain damaged and swam upside down in my fuge for a few days before he croaked :( Sorry McCosker's wrasse! Beware!.