Crystal City…
After Henry completed the summoning, he immediately arranged for Rachel to do the patrol just like the others. After all, at any time, a battle might just erupt. And of course, Henry was not willing to have the territory that he was currently in suffering any useless losses.
So, although it was true that it seemed too overpowered for several diamond rank monsters and humans to be patrolling the entire territory, there was nothing like too much of something in the apocalypse.
It was better for him to be cautious, rather than being extremely arrogant and ending up suffering. So, as long as he took early precautions, he was going to avoid unnecessary losses.