Eh I disagree. I think it helps to have someone who is big/physical to clear the crease in general but that pair should be able to make enough plays with their sticks then make a quick transition through either skating the puck out or clean outlet passes to clear the zone that I think they can (and honestly should) be able to get by. I don't really consider Braun all that big or physical and the Vlasic/Braun pair was dominate up until the last 2ish years.
The reason I think Karlsson is so effective from a defensive standpoint is he has a ridiculous ability to get pucks out of the zone and in transition either skating it out or with slick passing. There is no reason Vlasic shouldn't be able to win battles in the defensive zone, get Karlsson the puck and move it up ice.
Despite what you think of Brauner, he is the heavy part of that pair. 5th tallest player on the team, 3rd in hits and 1st in blocked shots. Compare this to MEV who has 9 hits all season. Braun is undoubtedly the physical presence on that line. That said, the biggest problem with Vlasic/Braun right now, isn’t that either is “bad”, it’s that they don’t fit the current system.
Compared to the other two defensive pairs, that pairs problem is two fold:
1) Can’t get the puck away from the other team. Roughly have the number of take-always and exit attempts per 60.
2) When they do get the puck, they rarely fail to clear, but end up with a dump-and-chase that leads to a turnover.
Back in TMac hockey, they would rarely try to hold the blue line, and were much more dependent on the forwards to retrieve the puck. Now we almost always have at least one forward pushing up ice to accept a stretch pass. Burns and Karlsson are great for this. They force a turn over down low by having their partner play the body, and then have the skills to lead the rush back up the ice to the waiting forwards.
Vlasic and Braun, together, can’t. That’s just not their style. Never has been. Your right that Braun doesn’t have the same wreckless physicality as Dillion or Simek, but he is much better defensively. Vlasic just doesn’t have the same play making abilities as the other two, and can’t take on that role.
I don’t know how you fix it. I think with the right partner Braun could still work. I don’t think Vlasic plays the right style of hockey for this team though. Maybe with someone like Weber, but that just furthers the notion that he needs to go.