Teamwork
After the Chi Branch member and his brothers vacated the courtyard, they did not hurry to leave the courtyard area. Instead, they went to the courtyard next to the one they just vacated and called out a challenge to the residents within.
Most people in the courtyards were equal in strength. At least the ones from the fifth courtyard and beneath had no particular advantage against one another, and they did not care for what number their courtyard was. All that mattered to them was whether or not they were capable of staying in this area.
It was only the top five that cared about their reputation and who would fight for the sake of taking over each other's numbers. So while it would be a challenging fight against the ones in courtyard number eight, it was not impossible for the Chi Branch member and his friends to win the battle.