Yes, you can keep different types of butterflyfish together. While there are many types of butterflyfish that can live well together when placed in the same tank, certain species are more aggressive than others. This aggression may be exacerbated when kept with other fish of the same species. Care must be taken when deciding which butterflyfish will be kept in the same tank.
Copperband butterflyfish, for example, do better when they are the only butterflyfish in the tank.