Although the Dodgers are the worst of the three division leaders, they have arguably the best squad of them all. They have the best batting average of the three leaders, and are second in ERA. Isn't it surprising that all three division leaders have the top three team ERAs in the NL? I don't believe so. But you need offense, as well. The Dodgers have both, and seem to be the hottest team in the NL.
The Braves and Pirates have their flaws as well. The Braves rely too much on the home run, which could be a problem especially if you have one bad game. The Pirates are almost the opposite, as their pitching staff carries them, while their hitting has not been able to keep up. In 2011, the Phillies had a similar team, and they got eliminated in the NLDS. I'm not saying that the Pirates aren't good enough, I'm just saying that being a balanced team better than being hitting heavy, or pitching heavy.
I think the Dodgers are the most balanced team in the National League. They have a pitching staff that includes Clayton Kershaw, Zach Grenkie, Hyun-jin Ryu, and Ricky Nolasco are all very good pitchers and don't disappoint when they are on the hill. Offensively, LA has stars like Hanley Ramirez, Adrian Gonzalez, Carl Crawford, Matt Kemp, and Andre Ethier. And, I didn't even mention their up and coming star, Yasiel Puig. This team is built like a championship team, and I think they will be able to reach their expectations.
The National League has plenty of tough teams, don't get me wrong, but I believe the Dodgers are the hottest, and could play the most consistent post-season baseball when October comes. So yes, I think the Dodgers are the National League Pennant favorites.