I have five RC parishes just south of Cork City in my database, and, until 1880, the various priests used the following spellings for what was clearly taken to be the same name: Carakawn, Hourican, Hourihan, Hourihane, Kerecwan, Kerrucane, Kerrukan, Kerucan, Keruchan, Keruchane, Kerukan, Kerrukane. One priest recorded the name twice as 'Howard'. Speakers of Irish may know why the initial sounds written as C, H and K were understood as being the same. I see no example of this name being confused with Horrigan/Horgan or Hanrahan.