Yup i believe its to fit into the lore of Middle-earth! The human is no lowly man, he is a Dunedain, so he sure to kick some ass!
I hoping the elf doesnt use too much 'fantasy magic' LOTR doesnt have magic on the scale the mages were shown to have in LOTR: Conquest! Gandalfsays in Fellowship (Book)"I cannot burn snow, I must have something to work with"
So yeah the classes are race based to fit to lore of the books. And even films, which might increase a few things NOT in the books!
But this is shaping up more and more to be a contender for MY Game of the Year!