5/6. Lenglen and Moody
Serena's low overall tournaments won number hurts her big time. At her peak she is right there but greatness is measured by numbers and her numbers do not stack up. Majors are the pinnacle but she would need to win more than 20 of them make up for her lackluster dedication outside of them.
Lenglen and Moody are from a different era when scheduling and things were totally different as was ease of travel. They both decimated everybody in epic ways and you can say they don't stack up but they were dominant in their era and until Court came along were the standard.