No, I have never tried to house anything with my paddle tails. The well being of my animals is not worth any risk, and since both species don't have the same care requirements I see no point in pushing the envelope. CFB's are non aggressive, small newts. They are also brought into the country for the pet trade in very unhealthy conditions. The likelihood of getting one in good health is, in my opinion, low. I do have 2 Co's and like them very much. I think they are a good newt species to keep and if you want some I think they are a good choice. Just make sure you quarantine any new additions, and don't mix species.
Oh, and newts like cooler temps, temps that are far too cool for frogs. To meet both species requirements they would need to be housed in separate tanks. I would strongly advice you to get a tank thermometer.