I'd have to look at the free agent list to confirm this but off the top of my head Pesce is the guy I want arguably the most in free agency, certainly the most in terms of the defensive market.
The Leafs have good pieces on defense Rielly, McCabe and Benoit are all good pieces.
What they not have is the guy that pulls the defense together.
If you can replace Brodie with Pesce that is a BIG step in that direction.
Having Rielly Pesce and McCabe as the top 3 would be a very solid top 3.
Then ideally you have Benoit anchoring the bottom pair
Your defense would look like this
Rielly Pesce
McCabe?
Benoit?
Or option B
Rielly?
McCabe Pesce
Benoit ?
Now if you went with option A you could put Benoit with McCabe because they played last year together and it worked, Benoit turned out to be a fantastic find for Toronto.
I didn't do that with option A because I wanted at least 1 guy on each pair but you could we know it works.
Option B still leaves the question of who plays with Rielly but I think McCabe and Pesce would be a hell of a shutdown pair.
Regardless you would still have a couple holes but Pesce would do A LOT for the Leafs defense over the next 4 years.