I am with Grins and Subliminal on this one too, you should not add anymore fish to that tank at this time. A dwarf angel shouldn't be housed in anything smaller than a 45 or 50 gallon tank IMO, I know Liveaquaria says 30 gallons but that is bare minimum I would think. I think clown-lover mentioned that his Coral Beauty swims all around his 75. I can say the same thing when I had one in my 100 gallon, she swam around like she owned the place too. I tried mixing a flame with the Coral Beauty, that lasted two weeks. The Coral Beauty was always picking on the flame, she wouldn't stop harrasing him. I think that is why the flame died ultimately. I like to think a 100 gallon tank is on the larger side (above average anyways) and mixing the two didn't work for me, so I would not recommend trying it for anyone else.
Food for thought.