Tolkien clearly couldn't present us with our Pagan myths in their pure form. If his was not a Christian mythology it couldn't
deny the Christian worldview. So things get left out or adapted to fit. A 'dubious' figure like Odin gets split, his positive aspects coming out in Gandalf & Manwe, his negative ones in Sauron & Saruman, Ravens make an appearance in TH, but are omitted from LotR - they have too many & too powerful Pagann connotations.
Like Lewis, Tolkien was happy to present us with Pagan things, but only if they were sufficiently Christianised as to make them safe. As Flieger stated in regards to Tolkien's ambivalent attitude to Faerie
http://forum.barrowdowns.com/showpos...&postcount=197 (he was both attracted to it & could see the danger in it), Tolkien's relationship to his sources was complex.