well i did look it up and danu wasn't a major god, a few others weren't either. whys that? And who is fingal supposed to be. is he in the mythology of celts? And I like scandinavian mythology cuz its really interesting to me.
You are correct, many of the names are of lesser Gods. Reasons for this, that I am aware of off the top of my head, are that A) Not everything we know about them is as clear cut as other pantheons. It appears much remains unknown about numerous deities and heroes. B) Mythology from the British Isles was quite different from place to place, so what may be an important God one place may be relatively unknown elsewhere. C) These are some of the more recognizable and memorable names, thus they were selected.
Fingal (Scottish) is transcribed as Finn McCool in English. He is present in Scottish, Irish, and other nearby folk stories. He is a hunter and warrior and led the Fianna. Legend has it that he never died, rather he and the Fianna sleep somewhere below Ireland waiting to be awoken. Finn and his story has subtly crept into Celtic Heroes over the years.
Scandinavian Mythology is really interesting, you are correct.