Just because your fish have had no problems doesn't mean that's everyday stuff,
Ain't that the truth. I have 2 gold gouramis and 2 paradise fish in my 55 and they get along fine. But, I probably wouldn't pair them up again like that, because I got lucky, I think. I had all 4 of them from the time they were about a half-inch and they grew up in a 20 gallon.