Wither the American woman

I am not certain whether this discussion should be in history or books.

Am reading a volume of archetypal criticism by Annis Pratt and am struck by her citation that so many of the Greek myths involve rapes because as the Achaeans came into the Greek peninsula, they overtook the local goddesses, mating or marrying them to their own male gods. We all have known this for years.

I wrote my thesis on a figure in Celtic literature known as the Sovereignty Goddess who grants the king the right to rule. She appears in the myth of the Ui Neill, for many generations pretenders to the kingship of the entire island, as the hideous guardian of well. When the first of the three Ui Neill brothers asks for water, she demands a kiss. He refuses because of her ugliness (a physician presented a paper at the Harvard Celtic Collequium on the similiarity between the description of the crone and the symptoms of advanced scurvy). The second brother brushes his lips to her cheek. The third brother sleeps with her and she reveals herself as a beautiful maiden known as the soverignty and he founds a dynasty.

Why is this so different than the Greek myths?