No argument at the top but have no idea how you have Serge ahead of Cernak?
Cernak makes rookie mistakes. Sergachev is making the same mistakes that Hedman made when he was coming into development. He's got to learn what he can and cannot get away with, otherwise he'll never fully develop. It's like a game of roulette as the coach. You let your d-man develop and pay the price on the short-term, or you limit them and force them to play very, very defensively and never let them develop from an offensive standpoint like Hedman has over the last few years.
Cernak is only 'below' Serg because of his rookie mistakes. You'll see him not read the ice correctly, or make a pass that has you going "WHY?"... He's only played a handful of games, so it's acceptable.
I'd say Cernak is the new "Coburn" without question. Over the next few years he'll be a very solid addition for us.