What does it mean if you can’t recruit without a group?

It means that the imperial court recruits talents with courtesy and hires people who are pure and noble, who do not follow the trend and are detached from the world. Today it also generally refers to the character of personnel required for recruitment.

From "Shishuo Xinyu", inheriting a young man and cultivating virtues, elegance and uprightness, it is true that he is not a group, and recruitment is not successful. Those who come after hearing the virtues are like a forest.