there are many differences in the movies, many that only
Tolkien's fans would notice or care, fair enough.
But some inconsistencies can be notice by anyone, regardless of how much they know about the real stories.
At the beginning, there are 3 sequences, nearly at once that make no sense whatsoever.
1)
Merry and
Pippin accidentally jump into
Frodo and
Sam, they are pursued by the
Nazgul and then they decide to join them on a trip that nobody knows where it ends, with obvious dangers along the road. No preparation, no
food, no idea where they are going.
2) While casual viewers don't know what the
Nazgûl are, and at that point not even
Aragorn's very short explanation has happened, but they are obviously very dangerous and the
hobbits are clearly no match to them.
Yet, Merry just throws a rock and the Nazul runs away.
3) They cross the Brandywine, the Nazgul are hot in pursue, riding
horses, the Brandywine bridge is only 20 miles away, yet, magically, the hobbits arrive in
Bree, unmolested. Bree was at least one day away, and the Nazul lost their track? or did the hobbits outrun their horses? (what know what really happened in the
books but that's not what happened in the movie)
No need to reconstruct the tale of
Tom Bombadil (which is important for other reason, but that's for another time), but they could at least show they weren't going on the road, omit
the old man willow and
Tom if you wish, but they needed another way.