Well it does depend on the personality of the particular fish.My male C.gachua will even try to go after my fingers while my friend keeps a C.gachua in a 75 with some bichirs and it doesn't seem to care and even piles with bichirs.
I KNOW IM LATE BUT I HAVE ACQUIRED A LOT OF KNOWLEDGE ON SNAKEHEADS IN 2 YEARS
DONT KEEP CHANNA PARDALIS WITH ANYTHING
THEY ARE SUPER AGGRESIVE
IF U PUT A COUPLE OFTHEM THEY WILL PROBABLY KILL EACH OTHER