My first 'BIG' tank. It was a 110 Gallon Tall 48x18x29. This was 35 years ago!
I put a 2" Volitans lion, 2" Panther grouper, 2" Red Emperor Snapper, 2" Orbiculate Batfish, small Undulate Trigger and a snowflake moray eel. I called it my 'killer tank'.
Surprisingly, they all got along fine. (Despite the Undulate trigger rep)
I kept that group for over 5 years. The Lion and Panther grew over 12". I had to give away the snapper to the LFS when he got even bigger.
I sold the system when I went off to school but, I loved that tank.
On the Frogfish note. I used to go to the beach and collect local fish for my tanks all the time. One time there was a large amount of Sargassum seaweed in. I caught 10-12 Sargassum fish. I was so excited. I put them all in a 55 gallon tank. They were all about the same size. The next morning I had 1 Sargassum fish. They all swallowed each other. DO NOT underestimate the size fish they can swallow. I would swear they can swallow a fish larger than themselves.
BTW: The Sargassum died of indigestion a day or two later! Gluttony is not good!