As for Yiyi's selection reason, it's not simply because of Xuerou's recommendation, but because loyalty was considered a factor.
The school's robots and central computer evaluated Yiyi as having top-notch loyalty, comparable to a rock in a pit.
A person who, from learning to walk until entering middle school, never changed their taste, hobby, or even favorite color, is a typical persistently single-minded individual. Such people may not make significant contributions in an organization, but you'll never need to worry about them defecting at the last moment.
On the contrary, at critical moments, she can sacrifice personal interests to protect people or organizations that are crucial to her.
As for Ye Heng, his selection met the criterion of mediocrity. After over ten years in school, aside from the Spiritual Fruit Garden incident (which may have hidden truths), his performance has been steady and unremarkable.
