AbdulAlhazred
Legend
Wait a minute! How 'random' is it when the GM drew up the encounter table and made bandits (logically, I'm not criticizing it) the most common type of encounter? And there are going to be multiple chances for this to be rolled, at some point, while the GM has not literally dictated this exact instance of it MUST happen now, they've in effect engineered the overwhelming likelihood. Beyond that, I've read plenty of "well, sometimes I don't use the dice" statements, which again is fine, I imagine plenty of reasons for not doing so in all cases.But the kind of prep we're talking about here isn't, "These bandits will be attacking this caravan when the PCs arrive on scene."
It is instead, "This is a caravan route, and there are bandits that prey on some of the caravans." One of the most likely way this will actually impact play is via a random encounter with bandits.
But beyond even the above, what happens if the bandits are not encountered? They just become a bigger and bigger threat, following some straightforward extrapolation, until finally the PCs WILL be called out to deal with them. It is super easy for the GM to build an overall situation which makes this inevitable, and 'plausible'. This is why plausibility, though necessary for a game to be comprehensible in play, is a weak criterion.
Now lets consider the Narrativist case and the trad LW case in contrast. What we find is that a bandit encounter in, say, my Dungeon World game, might easily arise. A player would describe through a bond/answer to a question/story they tell around the campfire how these bandits exist and are somehow part of his agenda, or maybe the GM would make a hard move and, say, they kidnap the dwarf's sister. Oh, but the dwarf previously was friends with one of the bandits, does he go wipe them out? In LW by contrast the GM thought, "bandits are a stock element that can develop into something, or at least be a fun encounter" and they go on the encounter tables. Later some story reason arises, like the dwarf's sister got put on a caravan and it was attacked. Why was THAT caravan attacked? Guess why!
In the end, it is a question of how the soup is made, not what the ingredients are.