It feels like Treliving had a case of tunnel vision with this signing: Roy and Pesce both signed for $5.5M and 6y and, while there's no guarantee either would sign here, I think I'd prefer either of those deals.
Tre wanted his man from Calgary, though. GMs going back to players they know and like (look at Dubas in Pittsburgh: he just signed Mac Hollowell). The positive is that Tanev is still a very good defenseman. For how long? Well, that will make or break this deal, won't it?
If Tanev can be a top-pairing D for the next couple seasons, be top 4 for another one or two after that, and then is a liability in years five and six, do you take this deal? I think my answer is yes and I suspect the Leafs have made that same calculation. It's a gamble, but it isn't one without upside. If the chemistry works, Rielly's game could also reach a new level when paired with Tanev.