In any case, they would move, and then when the merchant caravan came to a stop, they would find another merchant caravan to travel to the next location.
By getting on one merchant caravan to the next, they were able to move very efficiently.
Each place's merchant caravan schedule was placed at the top of the list for information collecting. Occasionally, they would go back a portion of the way to a previous town and then move to the place where a different merchant caravan was it seems.
After the other three asked why they should return, it seems Aisha responded like this.
"It's because this way is faster."