I don't see what the problem is with keeping Broberg. Just trade kulak for another righty. We lose our 3 bottom D, and gain new hope. Organic improvement with broberg on the left side, starting on 3rd pairing. We're deep there to cover for injuries. The new additions on the right side, can fight for 2nd/3rd pairing. It's not like it's hard to upgrade Ceci.
Unless Kane is out all year, you wouldn't have the cap space to swap Kulak for another righty (unless they're making near league min).
If Broberg's back, then you're going to have to run
both him and Nurse with the likes of Stecher, Emberson, Brown, Kemp and maybe Lindstrom if you offer a PTO.
Ekholm-Bouchard
Nurse-Stecher/Emberson
Broberg-Stecher/Emberson/Brown
Brown
And again:
You will have no way to upgrade that. If Broberg caps out at a Valimaki-level player, your cup dreams are more or less dead.
If you keep Kulak, you're in a similar situation
to start with, but that extra 2mil + 2nd means you've got the cap space + assets to upgrade. Getting someone like Connor Murphy at 50% or even a guy like Will Borgen wouldn't be out of the question.
Compare the group above to this
Ekholm-Bouchard
Nurse-Emberson/Stecher
Kulak-
Murphy
Stecher/Emberson
For this upcoming year, which group do you feel better going into the playoffs with? For me, it's 100% the latter. If you don't like Stecher/Emberson with Nurse, you can also target a guy like Fabbro.