Couple of things here...
I really, really liked this chapter and I agree with the concept of it showing growth and how the Hobbits have come full circle.
Also, I won't compare the battle fought in the Shire with any of the great battles fought throughout Middle Earth, simply because I think any comparisons don't work when you think about the... deeply personal nature of the battle for the Shire.
And I wouldn't define the Hobbits as ignorant. Innocent, surely, but not ignorant.
Finally, the first time I read it, I never, ever thought that Sauman was behind it all. I didn't think he'd had enough time to create as much of a mess as he did.
Obviously he was a workaholic.