I'd say you should add three or so zebra danios. More danios would probably distribute the chasing from the boss danio, if there is one, so that'll help. I do suggest you get more tetras, too. A ripped fin or two isn't something to be too worried about, just keep the water clean for them. I don't know how big an ornate tetra gets, but assuming they're neon-size you can probably keep eight of each fish, at least. Is the tank planted? How much?