Maps have always been intimately tied with tabletop roleplaying games, and never more so than after the D20 wave, which practically required tactical combat to be played out on a grid-based map.
The One Ring however doesn't require a map, and in fact I'd argue that the use of maps aside from the Wilderland map itself, is potentially damaging to the game, especially if the players have a grid-based background. The One Ring's combat system is entirely narrative/abstract, to the point where it doesn't even attempt to concern itself with locations, figuring that the group will handle it on their own with circumstantial modifiers and common sense. That's all fine and well, however in larger battles or in places with slightly more complicated geography, position becomes important, as does the effects of those positions.
We played the first part of the Battle at Amon Naugrim (Part 1, Part 2) using the map provided by Rich H in his extension of The Marshbell. The map is great at giving sense to the area, but when it came time to plan the coming battle and play out the arrival of the first orcs, the map started grabbing more attention than it should have. So for the second part of the battle, I decided to try something else, as seen above.
It worked quite well, giving everyone a sense of the geography and placement of a considerable number of adversaries at the same time, which would otherwise have been completely chaotic.