When Zhao Yi heard how formidable Luo Zhijin described "He Sect" to be, he assumed it was some large "sect", when in reality it was small and was referred to as 'He Sect' for entertainment purposes.
He Mingcheng spent his whole life conducting research, and it would be impossible for him to devote much time to mentoring students.
He only took on a student every few years when a promising one caught his eye, and his mentorship was limited to offering advice on what they should study.
For instance, Yuan Zhongchen.
When Yuan Zhongchen was a freshman at Yanhua University, he met He Mingcheng in the library. After a brief chat, He Mingcheng discovered that Zhongchen's ideas were very unique and realized he had found a 'kindred spirit,' so he guided Yuan Zhongchen on what he needed to learn.
Upon graduation, Yuan Zhongchen, left Yanhua University.