Recently I was discussing novels with a friend, who said that all major characters should change and develop across the course of any good novel. But it seems to me that in LotR (which no SFF fan can deny is a brilliant piece of literature!), a lot of the major characters don't change that much. Let's look at the Fellowship:
FRODO changes a great deal as a result of the burden of the Ring, his wounds, and the hardship of the whole ordeal
SAM, MERRY, and PIPPIN go from being fairly average young hobbits to the heroes of the Shire as a result of all their experiences in other lands
GANDALF gets 'promoted' from Grey to White, but his personality remains much the same (one of the hobbits says this explicitly somewhere, but I haven't got the quote to hand)
ARAGORN goes from wanderer to king, but again his personality doesn't seem to change
BOROMIR remains proud, Gondor-oriented, and unchanging throughout, unless you count his dying apology for his action towards Frodo (which could have been just due to being away from the Ring's influence)
LEGOLAS and GIMLI remain much the same throughout, except for Gimli's change in his attitude to elves (and possibly Legolas's to dwarves?)
So it seems the only characters who develop much across the novel are the hobbits who leave their peaceful insulated existence in the Shire to travel across the world, meet all manner of creatures, fight in wars, etc. Am I right in this - thus either proving that development of all characters isn't really necessary or finding a weak point in LotR, depending on your point of view! - or is there some change I've missed in characters like Aragorn, Legolas, or Boromir?
Thanks in advance for any answers!