I think there's alot of assumptions that players can't tell if things are getting shuffled around, but its adding extra work ensuring that they can't tell.
If you have a bunch of generic encounters everywhere, sure, shuffling stuff around can be easy. But if you have your encounters married to your worldbuilding, its much harder.
If the cultists are looking for the ancient sword and they know its location, why are they in The City of Brass when the sword is not? And then you'll have to improvise. Having great improv skills are a talent but most players can tell the difference between things on-the-fly and things pre-written because of quality. Your descriptions falter or you give details you need to take back.
Rather, having a well-known merchant living in the City of Brass sell a map to the sword's location both gives players a hook and could possibly direct them back to the cultists, who are in their proper locations.