I hope that you don't plan on feeding goldfish/tuffies etc very often. They're bad for numerous reasons, mainly the chance of them spreading disease. Entertainment is fine once every couple months, just don't do it too often. Earthworms would be a much better choice and are equally as entertaining.
IME, packs of 2-3" cichlids are more of "killers" than 1 large one. For example, I had a group of 2" red devils that would kill anything in their tank, no matter what it was/how big it was. I kept the dominant male, which is now around 8" and he will actually tolerate tank mates. He gets in fights, but never actually kills things.
I'd highly recommend taking the remaining goldfish out. The way those texas are killing them must be very painful towards the goldfish. If you are really stuck on feeders, make sure they are properly quarantined and are relative to the size of your fish.
Ex: 3" fish- 1" feeders (guppies)
5" fish- 2" feeders (small goldfish)
8" fish- 3-4" feeders (medium goldfish)
12" fish 5-6" feeders (large goldfish)
18"+ fish- 7"+ feeders (feeder koi)
Basically, you want the entire fish to fit in the predators mouth, or atleast 3/4 of it. This way the feeder doesn't have to endlessly suffer.