I don't know much about Carroll Malone, apart from the fact that he wrote 'The Croppy Boy',   the version which starts 'Good men and true in this house who dwell, etc.'.

I have never heard of him being confused with John T. Campion before,   but I HAVE heard that his real name was William McBurney, and that version of 'The Croppy Boy' first appeared in 'The Nation'.

As far as I'm aware,   his version of 'The Coulin' is translated from the Gaelic, he didn't write it.

Maybe Campion DID write a poem called 'The Coolin Forbidden,   but Malone's 'Coulin' was always spelt Coulin, NOT Coolin.