Mine new Channa andrao, 8÷9cm long. I have 3 fish in 60 litres tank.
Biggest and smallest swim together. Third fish was beaten and it has fungus in wound.
I am thinking about moving them in 75 gallon tank (6 feet long) and buying more fish. I have 6 Channa fireback in 80 gallon without problems and ch. anrao should be less aggressive.
If its big enough and there are enough territories, you might be able to achieve it.
How long have you had the firebacks living peacefully? Any pairs formed?