Montour is an offensive second pairing D having a completely unreasonable season out of nowhere. Ekblad is a high name recognition value player who quite frankly, can barely skate these days.
Their defence is a pile of crap. Forsling is a decent defenceman, but he's tiny, soft, and not really an amazingly mobile guy either. They're playing Marc f***ing Staal in their Top-4D in the year 2023.
They simply are not a complete team. They've got waves of forwards who can contribute and that's carrying them. But they're so entirely beatable. Teams just aren't making it hard on them. If you run a fast, heavy forecheck at that defence, they will absolutely crumple and collapse. Neither team has managed to do that with any sustained pressure yet.
I think calling them a great team, built for the playoffs is giving them way too much credit.