Hi
I have an ancestor Arnold H born circa 1803. The family lived at Mullahead/Brackagh area. One of his sons John came to NZ in 1862. He accounts I think for all the Hodgens in the NZ phone book. I notice one of your families is Irwin. One of AH's grandsons (Arnold/Henry/John-Mary) married a Mary Irwin, b 1871 d 1962. The family lived at Cooley Hill. All three A/H/J are buried in the Mullavilly Church yard.
I am sure you have found there are lot of Arnold Hodgens. I am happy to give you anything of interest.