It’s real simple. Holl was asked to do way more than he was capable of with the Leafs.
Like Chiarot coincidentally, he’s a very serviceable dman, until he tries doing too much. It’s what always gets them both in trouble.
Right now, they’re playing the roles they’re good at.
Gostisbehere and Maatta are playing really well together, allowing Detroit to play Holl/Petry with Chiarot in a lessor role. One they’re suited to play.. As for Gostisbehere continuing to be this good, who knows, but he’s been a great addition, and like with Hronek last year, Maatta has allowed Ghost to do what he does best.