Undulate Trigger and others

Ok firstly, I know I went way over my head but I was just wondering. I have an undulate trigger in a 67gal by himself. Yesterday I bought a Niger Trigger and a Panther Grouper knowing full well that the Undulate is very aggressive. I was wondering, If I aqua scape the tank well enough so that there are a lot of caves and crevices, would I be able to introduce the Niger and Panther with the Undulate? If not, I have other tanks I can put them in.
The Niger is already eating and settled in his QT tank. The Grouper hasn't eaten as yet. It will only eat live foods until I ween it. He ate a black molly the same day I bought him so I don't think I could try to feed him another molly till maybe tomorrow. Or should I try to feed him now? He's about 3.5 inches and the mollies that I have are about 1 inch. I tried shrimp pellets but he just looked at it and swam off.

 

Well they're both roughly 1-2 inches larger than the undulate. I have them in QT now. Both doing quite well... The Grouper is usually in a corner so I'm a bit worried but I suppose that's within his nature to relax on the sand bed etc. (I hope). I may introduce them one at a time with the Undulate next week and monitor them.
Has anyone else had experience with these aggressive Undulate Triggers?

 

I wouldn't do it. Several friends on another site keep undulateds. All agree (based on their experience) that undulated triggers should be kept as single individuals in a tank. Your tank is a great size for an undulate. I would not try adding other fish. It is unlikely to have a good end.