From what I've read, Mantha has been pretty inconsistent in Detroit. Lazy turnovers and uninspired play seemed to plague him as of late. All of that said, when the guy is on, he can bury the puck as well as anyone. Washington could be a juggernaut if this all works out.
While I was disappointed with the Pens trade deadline, truth is, in order to get anything, they'd have to give up something. It appears they aren't willing to move anything of value, they have no picks and no prospects worth trading. On top of that, there are still teams playing in empty arenas and those that have fans aren't generating enough revenue to convince teams to take on salary. It is what it is.
Carter will help I think, especially given the injuries, but I just don't think this team is built to go through 4 rounds of 7 game series the way the other playoff teams, especially in their division, are constructed. The Caps and Bruins are big and fast and they can beat you into submission over a 7 game series. I don't know what the Islanders are because they will whoop the Caps but lose to the Pens. I guess we'll just have to see.