I think with real-world/historical gods, they shouldn't ever give them alignments, at this point. Like, if we look at 1E/2E, they got obviously wrong far more often than right, and from this little list, there's been ZERO improvement since 2E. I mean, don't they have anyone who did classics? Or Welsh/Irish mythology? Come on. They must.
In fact, I'd go further.
No gods, in any setting, should have alignments.
Instead, describe their ethos and how they act, and what their values are. Then the players and the DM can decide what alignments are compatible with them.
This would be huge for the Forgetten Realms, which in classist D&D polytheism fashion, has plenty of AWFUL-sounding "technically Good" gods, who just really don't sound good from their behaviour or beliefs like our good buddy Clangeddin, who believes genocide isn't a dirty word, it's a necessity (hey take it up with him not me!), who is, and I quote "Lawful Good". And you have people like Mask, who, frankly, is nicer and less horrible than a lot of the "Good" gods who (when not mysteriously dead), usually "Neutral Evil" (admittedly 5E did fix this to CN, that's interesting).
But just ditch the alignments, outline their values and beliefs.