Gonzo's is very misleading to me. He gave up 7 runs in his first start of the season. He hasn't allowed more than 3 runs in 11-12 starts since. Yes, I realize that 3 runs in 5-6 IP is still a high ERA, but he's been consistent and effective enough to win. Tillman has now had 2 starts where he's failed to get out of the 2nd inning...and Ubaldo couldn't get out of the 3rd yesterday. I don't think any of the other starters have had outings that bad.
Also, when you stack Norris up against other #5's in the league, I wouldn't be surprised if he was the best of the bunch. He's given them far more than I expected him to this season.
I really like Gaus. And he certainly seems to have a better head on his shoulders than Arrieta. He just needs to find consistent control. For this team to make the playoffs, they're going to need both Gausman and Bundy to carry them in the 2nd half, unless they trade for someone like Samardzija.