This is speculation that, once again, does NOT exist in the trilogy. Compare for example, the Silmarillion, in which the ultimate outcome is the ironic realization that the entire struggle of the elves against Morgoth which had occupied the narrative was a futile struggle doomed to failure, because Morgoth was a Valar and could never be defeated by elves or men. There is similar speculation about the nature of Tom Bombadillo, but ultimately there is no clear answer because the story never tells you who or what he is. Were Saruman and Radagast and Sauron also Maia? The story doesn't say so.
Nor were that the case, would it make the stories any more "Christian." A satanic allegory would certainly include angels and fallen angels.