Kou Wei suggested a group fight since there was no better option.
He and Wei Chunqiu had just gone through a fight against each other, and their ability was more-or-less affected because of it. Lu Mingshu had very weak basics and wasn't that strong to begin with. It would be hard for any of them to win in a one-on-one fight right now.
With a group fight, they could support each other. Even if they weren't entirely in sync with each other, it would still be better than a one-on-one because the barbarians didn't know how to coordinate at all.
But for each pro, there was a con: if they happened to lose this group fight, there would be no more chances to win, and they would all have to face a lot of pressure from everyone else.
The three of them made their way back to the center of the rooftop, where the barbarians had been staring into space for a while.
"Are you done?" the first harpy asked impatiently when they returned.