Fish compatability mollies and female swordfish

I have two blue gouramis, one male and one female. Two males in the same tank can be pretty aggressive, but my pair appears to fight sometimes too, but I honestly think that’s just how they act. They like to bounce off each other and go face to face rubbing their little barb fins together. I also have one pink gourami in with the two blue gouramis and they get along fine. Mollies are generally compatible with all fish except for the really aggressive species like chichlids and oscars and most species of freshwater aquarium swordfish are pretty aggressive also. I’m not sure why the swordfish would be only aggressive towards the mollie unless it’s something to do with it’s fin shape. Some fish, while not aggressive, can nip on the fins of certain fish because their movement and shape trigger their food response. If all the fish in your tank are getting along except the mollie, take it back and see if you can exchange it again for another fish in a species you already have. Good luck!