What she achieved 79-81 establishes her as a great player on hardcourts and, given her Californian tennis upbringing/culture, it is to be expected that cement would be her best surface.
A light bulb went on in my head after reading you post Andy. Did Austin's young start age and the surface she played on contribute to her injuries?
Evert grew up on clay, a kinder surface and didn't go full throttle like Tracy did at 14. Anyway, it's a thought.
As for the French: I wish Austin had competed in 1979 or 1980. After all it was Austin who broke that 125 match win streak.