Thank you everyone!
@AJC Those accounts all had small beginnings. Discover SL at $1,500 and AMEX at $2,000. I've helped my family members implement all the things I've learned from this forum, such as applying the AZEO method before applying for credit/loan and have at least 1 installment and 3 revolving credit cards to maximize credit score. In this case, I helped him acquire his third revolving credit card to maximize his credit score.