Chun Doo-hwan and Roh Tae-woo's children were actually good students, weren't they?

Chun Jae-guk (studying Chinese Literature at Seoul National University), the daughter of Chun Doo-hwan and the ex-wife of Yoon Sang-hyun...
Noh Jae-heon and Roh So-young are both from Seoul National University...
They likely received expensive private tutoring, but since there was no rolling admissions system back then and students were ranked strictly by grades, there probably wasn't much room for corruption. Considering how many children of the wealthy or powerful end up just studying abroad because they have poor study habits or low intelligence, wouldn't it be accurate to say these children were well-equipped with learning abilities and study habits?