Reading Celtic folklore, myth and legends

I am editing my Priestess novel. The story takes place in Edinburgh, but much of the lore is Irish from the Ulster Cycle. As much as it works, it is not the same. So, I'm reading Scottish lore proper. It doesn't have the same rich characters (the Dagda? Hello!), but I live with the horror or some Hibernian chastising me about confusing Scots and Irish lore (yes, I can explain a million times that I understand the differences or inject the kingdom of Dál Riata, and say I simply prefer the Irish lore, but wouldn't it make sense to simply show that in the work?
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 Ultimately, it's about respect, for the lore, the people, and the author.