one the flip side of the coin...
dominoes are extremely agressive, mine is nearly 4 inches round and competes with two tangs only a little larger than he.
i don't know if your setup could last forever...need more specifics about tank size, but if you get a juvi trigger and have the domino in first plus have a roomy tank, you should be fine.
i'm pretty confident that after watching my domino for 3 years now master the tank, he would not let any fish sneak up on him for lunch!
heather