Well if it's a team friendly contact then it doesn't really matter, but I see no reason to assume Toews will sign a team friendly contract. When I think about what term I'd want for a player, I'm assuming they'd be signing at the market rate for whatever level of player they currently are (in this case 2nd pair defenseman).
Also, you're the one who brought up Bura, Kadri and Nichushkin, not me. And for Bura and Nuke, just because they were RFAs doesn't remove the risk. They could easily have made unreasonable contract demands or gone to arbitration to get to UFA status. My point is yes the Avs identified good fits with those players, but in all three cases they were also acceptable risks because they weren't stuck with any of them long-term. Toews on a long-term contract would be a much greater risk. Oh, and you can't dismiss Connauton and Rosen as example of poor talent evaluation and include Nuke as an example of good talent evaluation. All three were acquired as depth pieces. One worked out and the other two didn't if Rosen or Connauton had turned into good players for us, you'd be trotting them out now as example of how the Avs are good at evaluating fit. Maybe it's a coincidence that those two are defensemen, and maybe not. Maybe it's just harder to figure out in advance if a defenseman is going to fit with your system and mesh well with your roster. Heck, even just fitting in with the dressing room can be a factor.
Look, obviously a 1 year deal wouldn't be ideal. But I prefer the risk of him walking after 1 year to the risk of having a player signed to a long-term deal who isn't a good fit. There's a reason that free agency is such a crap-shoot. You never know until the player is actually on the team whether they will be worth the contract you gave them.