The group went through the industrial district fast. It was a blur of shattered concrete, spilled blood, and screeching Rift-Sprites. Reidar's Bone Militia and Rift-Sprite Squad went through the monster hordes, but not without difficulty given the large number of creatures he had to take care of and the number of people he had to protect.
It wasn't just that. The number of Rift-Sprites, in fact, exceeded Kate's predictions, by quite a large margin at that. Despite those being low level, they forced Reidar to use more mana than he anticipated, but the additional challenges also spurred his companions' growth.
All of that pushed more and more humans to reach level 5 and to join his party, which made things even simpler.
By the time they reached the residential zone, every survivor in Malcolm's core group had hit level five, and so did Reidar's group.