I always thought Sehanine was the goddess of the moon's penumbra. Since sehanine is god for mystics it only makes sense that she would be in charge of something ethereal. I made a up a fanfic once to explain how the division took place.
It's never been clear how the human gods and gods of the demi humans have been able to share the same porfolio. Death, sun, love, time . . . . Lots of examples of humans and demi-human portfolio overlap.
I the 3rd ed faiths and pantheons it was sometimes implied that at least some gods that shared to same portfolio were really just aspects of the same deity. The human and eleven goddesses of beauty share both bathe in the same pool for instance.
Mulhorandi deities are interloper gods and so a conflict could take place at some point.
