Leaving the Randall Stronghold was rather easy.
Since the wooden wagons had crossed the one-way portal alongside Thirteen's group, traveling in a group was possible.
Nearly all the Wanderers who were with Diana also had Avatars of their own, so they had something to mount on.
As for the Goblins, Lizardmen, and Ratmen, they also had their own mounts, which they acquired by hunting when they first arrived at the stronghold.
Diana's former comrades were still wary about the monster outbreak, but after she repeatedly told them that there was nothing to worry about, they reluctantly agreed to head to their next destination.
It wasn't really that hard to convince them. Their second mission had a time limit, and it only had to be brought up. So whether they liked it or not, they had no choice but to leave the stronghold. Even without directly bringing it up, they also knew that if they stayed behind any longer, they might fail their mission.