Great observations, Brian. Thanks to all for chiming in. Great comments... Grim, Overread, Onyx, Extollager, Hugh.
I knew these similarities subconsciously. Those type of comparisons exemplify my exact problems with The Sword of Shanarra and The Dark Tower trilogy. Then again, it's his world... his story.
I read The Silmarillion when I was fifteen, long before the internet, and I considered it canon... absolutely canon. Regardless of how many words are JRRT's, CJRT's, or a ghostwriters, it displays Tolkien's propensity towards a number of themes and plots. Angels, demons, elves, dwarves, orcs, trolls, spiders, dragons, evil, seduction, fidelity, sanctuary, fighting the good fight, desperation, honor, north and west versus south and east, war, peace, physical height or lack thereof, the sea, the call of the sea, the forest, rivers, the sun, the moon, light, horses, hunting, horns, a longing for a real home, unexpected friends and allies, palantirs, swords, elven magic, kings, sieges, battles, ambushes, and the physical/geological/topographical affects of evil.
Tolkien also loved threes.... Three, it's a magic number.
Three Silmarils.
In the ages of Middle-earth, time is divided by an almost regular three thousand year (at least the second and third ages) cyclic culling of the nastiest villains...eg. Melkor (before the arrival of the three kindreds of elves in Aman), Morgoth (the First Age), Sauron (the Second Age), Sauron and Saruman (the Third Age).
The elves are divided into three kindred... the Vanyar, the Noldor, the Teleri. The bravest humans were divided into three houses of elf-friends... of Ladros (Beor the Old), of Brethil (Haldad), of Dor-lomin (Marach).
The elves of Beleriand founded three hidden kingdoms... Doriath (Thingol, Dior), Gondolin (Turgon), and Nargothrond (Finrod, Orodreth).
There were three acts of kinslaying by Feanor and his sons... Alqualonde, Doriath, and the Havens.
The Noldor split into three factions... Feanor, Fingolfin, and Finarfin.
Midway through the Third Age, the Kindom of Arnor (Aragorn's ancestors) divided into three rival kingdoms. The humans of the late Third Age, Frodo's time, were divided into three kingdoms... Gondor, Rohan, and Dale. The remnant of elven leadership of Beleriand ruled in three areas... Rivendell, Lothlorien, and Mirkwood. (My impression is that not many elves lived permanently in Lindon. Those that did (Cirdan), were even more removed from the political realities of M-e than the others (Elrond, Galadriel & Celeborn, Thranduil).
The host of the Rohirrim was divided into three eoreds (columns, battles, brigades).
Frodo offered the Ring to three people... Gandalf at Bag End, Aragorn in Rivendell, and Galadriel before her mirror.
Sauron launched a three pronged attack against the West... north against Dale and the Lonely Mountain, central against Lothlorien, and south against Gondor.
There were three political offices of the Shire... The Thain (the patriarch of the Took family, commonly called The Took), The Master of Buckland (hereditary title of the Brandybuck family), and the Mayor of the Shire who presided at Michel Delving. After the war, Pippin became The Took and the Thain, Merry became the Master of Buckland, and Sam became the Mayor. These three were acclaimed by the Shire as the three captains of their liberation from Sharkey.
We could talk about twos, fours, sevens and nines as well.
I do not know how much of the repetition of numbers or the events, peoples, and places mentioned by Brian were intentional, circumstantial, or serendipitous. But I do think trial runs and failed/aborted missions were a part of his style. (i.e. You rarely get it right the first time.) I can see Gandalf's sending a Hobbit to destroy Smaug as a test to see how a Hobbit would do against a great villain. I can also see Gandalf (an angel) receiving a prompting to use Hobbits to defeat Sauron, but in his human guise he does not quite understand it... and sends Bilbo after Smaug.
Manwe fought many wars against Melkor before the rise of the two trees. He fought a war after Yavanna made the two trees. He fought a final war against Melkor after Ungoliant destroyed the trees.
The Noldor, the remnant of Eldar of Beleriand, the Numenoreans, and their descendants fought numerous wars against Sauron.
Never, in Tolkien's works, does a villain go down the first time around.
Turin got a lot of chances to get it right.
Turgon was sent many warning from Ulmo.
How many voyages did Tuor and Earendil make to find Valinor?
Even though The Silmarillion was published posthumously, the One Ring, all the Rings of Power, and the Arkenstone, recall the Silmarils. The allure... the subtle seduction was to be avoided before it even began. This is what Faramir meant when he told Frodo he would turn away from it even if it could save Gondor. The Silmarillion is titled after the three holy jewels... and the effect that they had upon those seeking them. Melkor and Ungoliant wrecked the lights of the world. Feanor tore the Eldar apart. Feanor's sons committed murder, kin slaying, treachery, attempted murder, attempted rape, etc. Boromir lost control for a moment. Denethor went insane with longing. Saruman was driven to treachery. Smeagol/Gollum committed any number of sins to get his precious.
The message we are to take from Beren, Bilbo, Gandalf, Galadriel (Feanor's neice!), Elrond (Galadriel's son in-law), Aragorn (Beren's descendent), Faramir (Beren's descendant), and Samwise is decide to reject seduction, unbalanced power, evil, sin... before it's existence is even known.
Tolkien is repetitive in theme and plot. That's his writing style.
He also borrowed liberally from myth and history.. Turin slaying Glaurung (Beowulf), Theoden's charge (Jan Sobieski at Vienna, the dividing of Arnor (King Lear), Boromir at Osgiliath (Horatio Cocles), the Valar (Tuatha de Danaan), Gollum (Judas), Numenor (Atlantis), Elendil's escape to Middle-earth (The Aeneid), Eotheod/Rohirrim (Goths), Maeglin (Ephialtes), the fall of Gondolin (fall of Troy), Hurin (Odysseus), Thorongil's raid (the Raid on the Medway)... I'm sure there are many more.