I prefer the maroon, I have a pair in my daughters 40G tank, they share the tank with a pair of dottybacks, a six line, and 2 cleaner shrimp. They have 2 6-8inch BTAs that they go between, they always sleep in the larger one at the bottom of the tank, and leave the other fish alone, but they were added last. Both the dottys and the maroons spawn regularly. I have never owned a tomato so don't know how they would do, but if your pair are on one side with a nem then they might leave it alone.