Welcome, Purplecat. I don't think I would worry too much about the spats. Although my herd gets along fine, I believe animals will learn to co-exist with one another. They can't really be duking it out all the time in seriousness, so maybe it is just a form of rough play. You could supervise the skirmishes, and let them know you ARE NOT a fan of intra family fueding...let them associate their fights with a loud unpleasant noise, and they may go to lenghts to avoid bringing it on. Also, a third cat will upset the apple cart, probably in a good way. The triangle is easier to deal with- one cat is top cat, and the other two are not....couse, if you add 10 cats...well, that might work, too...he he he..