This takes us back to the earlier question of whether Aithirne was a real or a fictional character. Fictional and divine personages usually have names that fit their characters, like Hercules and Rumpelstiltskin, even though the meanings of the names may not be immediately clear to the modern reader.
You are right that real persons often have names which are independent of their characteristics and of their roles. But that need not be the case for royalty and clergy, where new names may be adopted on consecration or ordination. When and why did St Patrick start being called "Patrick"? I have no idea about naming conventions among the pre-Christian Irish poets and clergy, so, even if Aithirne was a real person, I would not assume the literal meaning of his name to be irrelevant.
> Sent: Sunday, January 06, 2019 at 1:09 PM
> From: "David Stifter" <[log in to unmask]>
> To: [log in to unmask]
> Subject: Re: [OLD-IRISH-L] The Athirne and Midir incident
> Names are independent of characters.