[Opinions] Replying for everyone :)
For us, Arin *is* a form of Erin but not a spelling variant. Just like Lionel and Leonel are versions of the same name but said differently, we have "ah-rin" for Arin and "air-in" for Erin. It's not a modern variation either (though I understand why new_chloe could easily think it) but an old one...
I think that accent could have a lot to do with it. Ora (you belong in Hufflepuff!?)I am surprised to see it's considered a feminization of Aaron, and twice as surprised that you pronounce Aaron "air-in"! That's a *very* popular name here and it's always "ah-ron".
Which makes me think accent might have a lot to do with it.
Names with similar sounds, we say Ashley "ahsh-lee" and Mariana as "Mah-ree-ah-nah"...
Piccadilly, I said "ah-rin" and "ar-ihn" over and over, and I think it's the same sound ^_^ Thankyou!
And Gracie, Thanks for saying that my name *is* Ah-rin and so it cannot be wrong :)