None of the players that carolina took on are difference makers. Hamilton's production accounts for almost all of these guys production added up. Andersen couldn't keep up a .900 average with a defense that is of similar quality as carolina's and raanta's 905 is also under Reimer's 906 so wouldn't call those upgrades. I would also question the judgement of someone that brings a guy like DeAngelo in a locker room full of kids. I would've passed on that, no matter how low the price tag was. Montreal's center line is going to be better than last year's, Danault is going to stop taking Evan's ice time (who is faster and more skilled). Weber is not lost, he's on the LTIR where is highest value is for the cap space he provides. Most discussions about him last year were about how slow he was and how he should be pushed to retire. What we have now is better than a retired weber, he's a cap boosting weber. In the end we'll only see what the result is once the season start but my feeling is that the right pieces are now in the right slots and the underachieving centers issue we had have been handled. As to the "who would want to sign in montreal" point you are trying to make, I'd just say Carolina doesn't have anything very bright to show in that sector either, nothing matching montreal's recent UFA signings anyways (toffoli, chiarot, savard, hoffman).
Start with the goaltenders, Freddie played behind a defense in Toronto that is FAR worse than Carolinas. Carolina's is one of the best in the NHL, they have one of the best defensive systems in the NHL. Slavin is undeniably the best defensive defenseman in the NHL, Pesce is right there with him, Bear, Cole, Skjei... these guys aren't bad in their own end either. Raanta's issue is staying healthy. He'll be great when he can play. Freddie is going to be a case of not overplaying him, hence they have 4 other goalies under contract including 2 prospects if anyone needs to come up and take the reigns for a few games.
TDA is also a kid... people forget that. TDA is a 50 point D man and he'll make up for the majority of the atributes Carolina lost with Dougie if he keeps his nose clean. Remember, Dougie was labelled as a cancer before he came to Carolina and look what happened with him, he's now viewed as one of the best D men in hockey.
To say Montreal is better down the middle is a stupid arguement. Evans may be better than Danault eventually, but Danault is one of the best defensive forwards in the NHL. His underlying numbers are incredible and Evans doesn't provide that stability.
Weber is lost. I get he's on LTIR and you get cap space and so on, but he's not there to QB the PP anymore. You do not have that 100 mph slap shot.
In terms of who wants to sign in Montreal, Chiarot is very eh, Savard is a French Canadian. Hoffman and Toffoli are interesting that you brought up, but are they better than the collective of Jesper Fast, Ian Cole, Josh Leivo, Jesperi Kotkaniemi, Derek Stepan, Fredrik Andersen, Antti Raanta? That's just this year too, recently they had Dzingel, Gardiner (who chose Carolina over Montreal) I don't know that I'd say that Montreal has better luck drawing in free agents than Carolina does, especially with the state that team is in right now.