Edmonton's cap hit for Campbell is currently 3,850,000 with him buried. By retaining 50% salary and taking a 50% retained Samsonov, they are instead paying a current cap hit of 4,275,000 for a serviceable goalie for the remainder of the year. But must absorb 2,500,000 for the next 3 seasons of Campbells contract.
Broberg get's a change of scenery
Is one first and some 2nds the right incentive?

The Leafs save 525,000 in Cap space for the current year, but take on Campbell for the remainder of the year plus 3 full seasons. Campbell making only 2,500,000, playing in Toronto where he performed well does become a strong bounce back candidate. As a back up anyway. The leafs would be able to 50% retain to another team as well. This would allow a team to have a full 3rd string option and zero cap penalty.

Minnesota gives up Spurgeon who's serviceability is becoming less and less likely as a 34 year old defenseman having hip surgery. Minny who already has the near 15 M cap penalty next year for the Suter and Parise buyouts could use another Cap break. Clearing the 7.5M allows them to be more aggressive in the offseason.
Minny gets a fringe winger in Robertson who may simply just need a change of environment. They also get a left shot defenseman in Broberg who may thrive in an environment with prominent Swedish D man Brodin and Forward Ericksson Ek.

The leafs taking on Spurgeon is risky. He is a LTIR write off for the remainder of the season and likely won't be ready come early next season. Do they accept a high risk of him playing again and taking up 7.5M of their cap? Or does he visit Robidas Island?
Leafs get veteran Fleury to assist Jones and guide Woll (if he get's healthy enough).
Maroon gives the Leafs that playoff edge and experience.
Middleton gives the leafs solid top 4 D experience. Is there enough here to acquire him?

Dubas get's some familiar faces back. Gives up Accari who should have been signed by the Treliving instead of Kampf anyway.
Brodie get's extended by Dubie.
Reilly Smith goes home