Rod Brind'amour plays a structured system which seems to have stifled Necas. MSL plays a loose open system within which Anderson has struggled. Carolina needs cap space and to keep competing. Montreal needs more talent and to start competing... See where I'm going with this?
Anderson (retained to 2.75m) + [X] + [Y] + [Z] for Kotkaniemi (4.5m) & Necas (RFA)
Anderson is a low risk physical player for them and arguably worth 2.75/3yrs if he was a UFA. CAR gets rid of Kotkaniemi's dumb cap-hit so between that swap, that's good value for them.
And they make [X] etc. for an unsigned Necas. I'm not sure what X, Y, and Z could be, maybe someone can propose something suitable for CAR. They don't want/need a goalie. Not sure waht they want. The 26OA and/or CGY 1st + Savard maybe? Beck, or any prospect not named Hutson/Reinbacher? I have no idea!
The Habs can hold onto mega-bust Kotkaniemi as a physical bottom6 player and use a buy-out on him in the following summer for a miniscule cap penalty of under 1m. If Kotkaniemi plays like he did early last season, it would be a rather low-risk, high-reward play right out of the bargain bin. If he doesn't, it would be the price to pay to get rid of Anderson and acquire Necas.
Necas isn't a superstar but he's the exact kind of deluxe secondary line talent who a team should bet on if the numbers/assets work.