I know this won't be much of a surprise on a lan
Greetings Mr. Morgan,
I know this won't be much of a surprise on a language-oriented list but I would suggest instead grouping or networking the gods by linguistic association first and foremost. Grouping by mythic theme is certainly useful but the problem is that the ancient peoples had common, recurring myths. They might apply such a myth to a god newly arrived to their pantheon, even if the myth has little to do with the god's "portfolio" so to speak. They may also apply myths or motifs to gods through a variety of happenstance, such as "well it SOUNDED like the word for well, so we just gave 'em the ol' 'overflowed the well' myth" and so forth.
Looking at the linguistics and evolution of god-names and god-titles often allows us to trace the cult and worship of a given deity as they migrate over time. Then we can look at the myths of each new region or age as a secondary factor, often gaining a lot of insight as to how they pick up or set aside certain aspects as they appear to new peoples.
Again, not putting down the idea. I love this topic and your game is a fun one. Just pointing out another approach as well.
N.B. Regarding, "There is clear evidence that Irish gods rejoiced in a profusion of synonyms" - rejoiced... and rejoice still! :)
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