After all, many Outer Realms were teeming with all sorts of giant creatures.
When conquering these Outer Realms, the Pinnacle Celestial Immortal Sect's high-end combatants either needed to conserve their strength or were tied up by other powerful beings, leaving them unable to help. Thus, the other disciples had to form teams like this to tackle the tough challenges.
These monthly exam rules didn't allow disciples to kill each other; instead, they had to work together.
At the same time, someone had to take charge of organizing, assigning tasks based on each disciple's specific skills.
Those with outstanding Body Refining Skills naturally had to act as human shields, taking damage and drawing the aggro of the large Alien Race members.
Then, of course, there were the frontline damage dealers, the ambushers, the support healers, and even those who handled logistics.
