Gryz is seen as a part-time top pairing guy. In 2021 he got more time with McAvoy than anyone else - 349 even strength minutes compared to Lauzon's 329. He's viewed as situational on that pairing and I think that remains the case. It's also known that he's going to get injured from time to time and can't be relied upon to be available to the extent that a guy like Chara was. Now it's simply hoped that Forbort becomes the new Lauzon as the guy who can play that more shutdown, more physical role when required while Gryz is the default 1LD and the playmaker who's especially used when the team is trying to drive offense.
In theory it's not a bad system, but it's contingent on Forbort being up to the task of taking on solid top pair minutes, which remains to be seen and on past performance is a tad optimistic, and on Gryz being able to work through heavier traffic and be as effective in playoffs as he is in regular season games, which to date for the most part he hasn't been. As long as Gryz stays fit and Forbort doesn't totally tank in Boston, then I'm pretty confident that Gryz/Forbort-McAvoy will be just fine in the regular season, just as Matt and Charlie were in the last one. But if Sweeney takes the same concept to the playoffs again, then I see no reason as to why it should work any better than it did this year. We're left looking to the deadline again for the GM to give the team all that it actually needs to have a fighting chance. That's frustrating to say the least.