There were only four people in Gu Xiqiao's team, and only groups of five or more could enter the selections. The others were obviously in their own family team, and most of them had ten or more to a team. The stronger the team, the better chances they had in Bahuang Forest, which also gave them a better ranking.
So for those who were alone, who wouldn't want to join a strong team?
But on the other hand, stronger teams had more criteria in candidates that they chose to let into them, especially those from the bigger families. They had to at least know the person, otherwise if they were to let a complete stranger into their midst, let's not talk about how awkward the stranger would feel, even the family teams would feel uneasy.
So for those bigger families, they didn't wait at the entrance to recruit anyone, heading in directly instead.
Those who stayed at the entrance were those with average strength and wanted to recruit more people for better chances.