I would have said the same thing except on the 10 minutes of play I watched, it looked like Rosen and Östlund went on the Quinn/Cozens workout plan this summer. Normally, I wouldn't have even said anything given the extremely small sample size, but their poor play was that notable, especially given the competition level.
And from what little I saw of Mrtka, I agree that he could push his development timeline. He seemed a step quicker and stronger than the Rochester D.
But small sample size I know.