Sun Yingping, as an outer disciple, did not actually take a master. He only practiced martial arts with the Chief Instructor. Strictly speaking, he wasn't considered a disciple of the Chief Instructor.
The Celestial Soldier Dao has hundreds of thousands of outer disciples. Once these outer disciples leave the Celestial Soldier Dao, they actually have little connection with it.
Sun Yingping was like this. His martial arts were mediocre, and he ended up destitute in Copper City, dying from hunger and cold. His end was rather tragic.
The key was to investigate Gao Xuan's origins, confirming he indeed was a disciple of the Celestial Soldier Dao, with a clear and legitimate lineage.
Pang Tong was a bit skeptical: "Can an outer follower become a Martial Arts Grandmaster? Moreover, considering Gao Xuan's age?"
