I don't think you'd have trouble with the purple. You might have more problems between the Kole and Powder Brown. However they are all from different families. I would maybe QT the Kole and Brown together and then QT the purple at a later time. I would also buy a larger Brown than the kole. Brown is probably the most timid of the two. Purple could be the most aggressive do should be added last. I would also try to find a smaller one, not too small though.