I went to the fish store, and talked with the guy extensively. He agreed that Mr. Swordtail might have stressed the other two to death. I have a plastic baggy with his name on it just in case he pisses me off. The store will take him off my hands, and I won't dirty my hands with his death.
So of course, it was time for new fish! I decided to go a different route this time. I have been fascinated with the idea of watching schooling fish... a nice group always hanging out. And I found them. I bought 6 of these guys:
Black Phantom Tetras. What a cool name.
And they're cute! So far, no real problems, except for a minor turf war with the Angelfish. I think they'll settle down nicely.
And get this, Mr. Swordtail has taken to swimming with them. Guess he's lonely. I'll keep him for now.