That's not something I was expecting... I mean, how unlucky can I be?
While every floor is different, they all possess one thing in common: They span infinitely.
Depending on which of the numerous paths you take, you may find stronger monsters earlier or reach dead-ends, but each turn you take almost always leads to several new options to follow, making a floor an essentially gigantic labyrinth.
And while there are dungeons that don't follow a cavern-like structure, due to their infinite span, the chances of meeting someone else will surely decrease as long as you venture farther and farther.
I can only think of two explanations that might increase the odds of meeting these guys again.
First, curiosity might've been at fault here. We took a chance at a path that wasn't on the maps, knowing it would probably lead to a settlement. Best case scenario, this was the same for them.
Otherwise... this was intentional.
