Spieth has a huge advantage on the greens over most men on the PGA Tour and and even bigger advantage over Lexi. I may get blasted for this, but the men putt way better than the women and certainly some weeks play much tougher greens than the toughest LPGA greens. There are only two LPGA players that average less putts per round that the top 50 PGA Tour players do.
I would agree with this completely. Can't remember if it was every shot counts or another book, but the biggest difference between the PGA and LPGA players is the short game/putting. the theory was that most men don't have to chase the distance the same way that many top female players do, so they spend a lot more time in their formative years working on the short game.