Norse Sól and Anglo-Saxon Sunna are female and their moon is male just like Lithuanian myth says the sun is the mother, the moon the father and the sun goddess is called Saulė.
But other Indo-European religions have male solar deities like greek Helios, Roman Apollo or Hindu Surya.
When did this divergence occur and was it the result of influences from other kinds of religions?
On a related note, what are some good books on general comparative religion/mythology, specifically not focusing on (or from the express point of view of Abrahamic religions) and dealing with historical religions as well (Sumerian, PIE, Turco-Mongol etc.). I've asked before, and didn't get any answers.