Just like many others, I was much influenced by the Clancys.
I can understand why someone would think they tried to make every song Irish, but their lovely accents do that automatically.
The only sour note I can recall is this: I owned their songbook, 35 years ago. All the songs in there were marked copyright(them,) and they were mostly traditional songs, some predating them by hundreds of years.
No, there were no arrangements in it, just a treble staff and guitar chords. I wonder if they really tried to claim copyright to songs like those, or if it was some manager chancing his arm.