Long post, TDLR: I don't think the defense is too slow overall and I think that while Schenn has proven to be a decent NHL player, he doesn't fit the Canucks style going forward. But at the same time, his skillset is hard to replace on this roster. It's a bit of a conundrum.
I've been thinking quite a bit about Schenn as I think he is a surprisingly good asset and for a while I thought they'd trade him at the deadline. But given the run they've been on it seems like they might not be able to trade him this season. Schenn obviously brings a physical game that not many other Canucks can bring and his positioning has been pretty great and the basis for his "resurgence". His passing is ok when he gets it off, but he really excels when keeping his game simple.
That brings me to why I think they'll trade him and the short version is his lack of both skating and his pace of play. Too often he handles the puck longer than he should and gets in trouble when a forechecker closes him down. Often this is when he has trouble picking the puck off the boards, receives a hard pass which he bobbles or takes an extra half-second to control, and sometimes he just takes too long to survey and make a decision. It's one thing if Hughes holds onto the puck because he can elude forecheckers with his skating and handling, but Schenn plays best as a one or two-touch player and that's not consistent. I think his positioning and physicality (particularly at the net-front) make him a good NHL asset, but I'm not sure the speed he plays at matches the style the team wants going forward. When Boudreau and management talk about wanting more speed, its Schenn I mostly think about. The problem is the Canucks don't have many other players with that physical skillset and the way this back end is constructed makes this a tough situation to rectify. If their other defenders (other than Hughes) were better than average skaters this wouldn't be such a problem and he'd be fine as a steady third pair guy.
Part of why I've been thinking about this is because I was hoping Hamonic would get back to a high enough level and take over on Hughes right side but the last couple of games has shown that hasn't happened and may not this season. If Hamonic could do that it would make management's job a heck of a lot easier by building Hamonic's asset value back up or allow them to trade Schenn for a pick that would help give them ammunition to reshape the team. I reckon they might even get a 2nd or 3rd for Schenn given he is on an almost league min cap hit and has shown he can still play dependable mins.