While there is some risk to signing players to a long term deal, this has been the trend under the structure of the current CBA -- a structure that I doubt will be overhauled in this round of negotiations.
What we have seen is that even if a player is overpaid, the increasing cap means that the FA market is increasingly pricy, making overpaid-but-NHL-caliber players become less overpaid through time. The apparent risk of a long term deal isn't actual. The marginal "dump" of an underperforming contract decreases through time and some "dumps" become hockey trades as markets move. Also, a number of teams need to take on salary to ensure that they are going to have a cap floor problem and some teams will be willing to take on a less-than-ideal contract to make this work. Other teams can't compete in the free agent market because they have undesirable FA conditions and must go through the trade route. The bottom line is that less-than-ideal-but-not-albatross contracts can be easily moved in today's NHL. And even albatross contracts can find a home for a cap-floor dweller. Finally, for a team like the Canucks that is willing to eat cap by reassigning players to the minors, the loss is borne by the owner but the valuable commodity known as "cap space" can be restored (here is where the Cancucks should worry about a change in the next CBA). The Canucks will take on other teams’ Reinprecht’s and Parent’s, etc. – so even if you don’t want to eat money, you can often find a team that will. At any rate, all of this suggests that long term contracts are rational decisions in a world of increasing caps, particularly for contracts that end when the player is 33.
Where deep pocket teams like the Canucks are exposed to the greatest risk of creating situations they can not maneuver out of is when GM’s are too generous with NMCs, and less so with NTC’s. (I don't know whether Garrison has one). While players might waive these clauses, there is always a chance that players will refuse, will control the destination (and limit maximum return) and there is a negative cost to asking a player to waive -- because it acts as a signalling device to other free agents that want an NMC/NTC. (I have a lot more to say on NMC/NTCs, but another time).
Bottom line – the term doesn’t concern me and I think the Canucks are much stronger with Garrison than Salo + Rome. He fits the second-tier versatile all-around model that the Canucks have based their d-core on during the GMMG reign. He fits into the salary structure for the purposes of respecting Hamhuis and Bieksa's contracts, and he is signed for his prime years.
If I have a concern, it is unrelated to this signing. It is that second-tier versatile d-man model may not be as effective as the 1D-stud surrounded less versatile contributors (the PK specialist, the shut down guy, the hitter, the second PP QB, etc.). But this 1-D stud player is almost never available in free agency. What makes this year a little different is that Suter arguably is this kind of player, or at least a lot of people think he is. I am not as sold on Suter (he’d be the Canucks best D, but I’m not sure he’s the guy I’d put all in with). So on the whole, I think GMMG’s approach of staying out of the Suter sweepstakes, getting another top 4 guy, and hoping Edler takes another step forward while Hamhuis and Bieksa do not backslide is reasonable. If GMMG wanted to adopt a 1-D stud approach, he’d do better in the trade market, but one has to assume any other team would demand Edler as part of the return.