CGY should probably do this but they also would prefer to trade each player individually I'd assume.

I have yet to ever see a team trade 3 of their top 4 defense to another team. If Treleving does do this his time in Toronto would be short lived.

2 yrs of Tanev before he is retiring.
Hanifin isn't re-signing in Canada supposedly.
Andersson is a good d-man but not worth all that.

sorry but dont see many takers for brodie, 33yo rental (@5m cap) eliminates all non playoff teams, and how many playoff teams have extra 5m cap and if do do they want to spend on defensive D man

3x 2.4m for 4C (close to 30yo), kampf doesnt get a lot a looks either

. . . on a contract that's 50% underwater, so that even with late-season pro-ration, it's still unattractive.

Both would be throw ins cap wise which I can see, that being said why would Calgary make the trade to have only 1 DMan signed next year, I don't think Calgary even entertains until Liljegren and probably MccAbe are added. Even then I am not so sure as those two don't replace 3 of 4 of top 4. Also why would Toronto do this when the odds of resigning any of the defenseman are not high. Hanifin will have at least 4 American teams willing to offer the same as Toronto maybe more. Ottawa and Vancouver are both said to be interested in signing Tanev over the off-season. Who knows who else might be interested. So that's a lot for Toronto to give up for just Andersson.

This trade would obviously never happen if Hanifin and Tanev aren’t re signing