The barrel scene in the book did not need to be another action scene, but the trailer is making it look like they're fighting in the barrels as they're going down the river (which is both stupid and probably physically impossible)
So you're moving on from "Man of Steel" to the "Hobbit"?
Did you watch the "Hobbit" Did you see the dwarves tossing CGI plates like they were nothing?
How about the dwarves sliding down a ledge on a rickety piece of wooden platform?
Or hanging on to a falling tree and everyone surviving. Not to mention giant eagles swooping in.
"Stupid" and "physically impossible" come with the territory of these movies.
So if they can fight in barrels going down a river then they can because it's fantasy epic.