A quick thought before I get back to class prep:
People frequently ask why Frodo didn’t fly to Mt. Doom on an eagle if the eagles could clearly fly him out of Mordor after the job was done.
Wiseguy: “Tolkien was an idiot”
Chorus: [appreciative lols]
Except Tolkien wasn’t an idiot. You remember the Eye of Sauron, right? Like a giant spotlight/radar on a huge scary tower? Remember?
If Frodo flew in on an eagle, they would’ve been spotted from miles away. The entire Mordorian army would’ve been waiting for them on Mt. Doom when they landed.
So, they had to sneak in, under the radar.
Which means no eagles on the way in (only on the way out, after the Ring was destroyed).
A theory of why Gandalf actually says “fly, you fools”
http://www.reddit.com/r/FanTheories/comments/130it2/lord_of_the_rings_a_theory_about_the_eagle_plot/
Fan theories are the best theories.
While I see your point on LOR and agree Tolkien was a genius, there is a plot hole (In my opinion) that I never understood. Why didn’t Sauron just keep some enemies on top of Mt. Doom? He has the orcs/Nazgul/Any other dark thing to spare? The hobbits aren’t good for combat and they try to avoid using the ring. Why didn’t he have at least one dark thing as a last resort or final gate?