Hello,
the most snakeheads are not wonders of socialization ... sometimes it works with a community where they are integrated, sometimes are not.
If not it's a bad time for other tankmates ...
I'm keeping only one snakehead (if you are keeping a breeding pair of snakeheads together no other fish will have any future in the same tank - definitely!) in every bichir tank - without problems. But these bichirs were always bigger than my channa or almost the same size.
The problem is not the fact that dwarf snakeheads (i'm speaking about
Channa gachua) aren't fisheaters - they are territorial.
It may be a problem that the bichirs or that big rope will snack the lil channa by night.
Another problem: Sometimes channa are aggressive against fish and on cannot see any reason for it - i had this with my Heteropneustes fossilis ... the channa cut his tail totally and seemed to kill the catfish. Peace came - curious - with the P.teugelsi ... it seems that it was clear that the teugelsi was the new "chief".
You see: It's not so easy! In doubt it's better not to do ... it works in my tanks but does it work in yours?
Greetings
Uwe