Rebuilding the defense is about volume. The more options, the better. My objective would be to liquidate declining assets and rebuild it from the ground up. Something like this:
Keep Hutton, Stecher and Biega (who is 30 years old and is fine as a fringe NHL/AHL dman).
1. Trade Edler to MTL at the deadline. Get Josh Brook back. That's a good right shot option added to the pipeline.
2. Trade Tanev for a right shot D or a 1st/2nd + D prospect. They need to trade Tanev this offseason because he is in decline and he has 1 year left on his deal. Get a Liljegren (unlikely, I know) or another D option back.
3. Move Gudbranson for another D prospect. If they can work out a deal with OTT to take on Ceci to get Jacob Bernard-Docker, that would be ideal. Or, target JBD alone if Dorian thinks Ceci has value.
4. Trade Del Zotto and Pouliot for D prospects and/or picks. Reasons are obvious.
5. Move any non-young forward for a D prospect and/or picks. This includes Sutter, Eriksson, Beagles etc... This provides a better chance to draft a Dman with those picks.
6. Stay away from any high end options on defense in FA. Re-sign Edler if he's not interested in staying in MTL. Maybe sign low end options at RHD like Sustr, Rutta and/or Jensen.
That gives you something like this for next year:
Elder-Stecher
Hutton-Biega
Hughes-Ceci
Juolevi-Jensen
Now granted, that defense is probably weaker than the one we have now, but it has Brook, Woo, Tryamkin, Liljegren, Bernard-Docker, Rathbone and other options in the system. Hughes and Juolevi are both in the top8 as well. The left side should be stronger, and depending upon what you think of Gudbranson, the downgrade on the right side is Tanev.