My Paroon shark was in a tank at the LFS with a small channa micropeltes. The channa took out his eye one day and i got him for free as he would probably just die there.
Got him on July 20th @ 4"
Now 5 months later he is one healthy, one-eyed fish @ 12"
I haven't done a rescue in years, but I was given a "8 inch" Oscar (turned out closer to 14") that I housed for a short while before moving him on, and tons of various Africans that people would bring into the LFS where I worked at the time.
Oh, my 5" aratus were beating up this 1" red zebra in my 30 gallon, you said they could live together.....nope, never said that, "well, just take the fish". I must haver had this once a week for 2 years.