Their infield defense is beyond awful. I find it hard to believe the guy who wrote that has actually watched them play. And no one in their right mind likes Atlanta's rotation more than Washington's.
I saw Atlanta's IF during the last series, and they reminded me of the difference between the Yankees infield compared to the Dodgers' infield in the '78 WS. Dodgers would not turn a DP, could not field under presure. Russel, their SS, complained, approximately, "How can you play when you have 55,000 people screaming for you to fail?" (Of course I thought that was what major leaguers did...).
But...why waste effort on some fangraphs guy's predictions? Doesn't a win count more than a prediction?