After everyone made their decisions, they chose a direction and began to move toward it.
Although they knew that afterwards, they would need more time to explore outside the wall, completing tasks that previously took them only half the time, they had no choice. If they didn't stay together, it was very likely that only one of the three teams would survive.
And the only way those people could return inside the wall was by sheer luck, avoiding encounters with powerful creatures outside the wall or the Power of Heaven and Earth outside the wall. But there's a problem: they didn't know the way back. That means it's almost impossible for everyone to safely return, and the odds are even less than them immediately entering the Taichu Realm.
After all, the scenery outside the wall hardly changes, so for everyone, not taking a detour is virtually impossible.
