How do they agree? They both believe being on your back is a guaranteed way to lose a fight with the judges in modern MMA (Penn's comments are in his book):

“I am completely comfortable to go to the ground in a fight,” he said. “I use my takedown defense because I have a better chance to end the fight using my hands. And if I’m going to go to the ground, I’m going there on my own terms, not on somebody else’s terms. I mean, I don’t care who you are, I don’t care if you are a BJJ black belt and a world champion at it, you do not want to be on your back in mixed martial arts anymore. Statistically it’s the worst place in a fight to be, the judges view it as you losing the fight regardless of what’s going on. So I’m not going to let somebody put me on my back, I refuse to do it. But I have no problems going to the ground whatsoever. If the fight does go to the ground I think people will soon realize the level of my jiu jitsu.”

As for Stann's jiu-jitsu, we'll see. But as much as it pains me to admit, he's right about how judges view being on your back and the guard. Even if you're throwing up submissions attempts and making it impossible for your opponent to pass, they view the back to the mat as a priori defensive position. To some extent it is, but I cannot erase from my memory the absolute robbery of Renato Verissimo in his fight with Matt Hughes. What I worry about is that even if judges become more competent about the intracacies of the guard and jiu-jitsu as a whole, fighters will follow Stann's path and alter their game so as to never be on their back as long as they can help it. I'd hate for a unique dimension of the game to be avoided because of a legacy of incompetent judging.