A severe overpay for Carlsson. He gets a third of his points on the PP. Leafs who have the # 1 PP in the NHL, really don't need this addition. Leafs need young additions soon, not a Dman with 2 full seasons on his contract. A competent UFA Dman can be had for 4m, and then the Leafs can keep their top prospect Cowan and the # 1 pick
Roy started a 7 years contract at age 30. Almost all NHL Dmen decline in their early thirties.

What ufa dman are you getting with 4m? Not roy, demelo or pesce. One of those guys are going to cost atleast 5 and they’re going to want term.

Just look at your post. You spend 9m on on Carlsson and Roy. Surely the Leafs can 9m on two competent Dmen without giving up assets like Cowan and a first.
Players wanting term? Look at Tavares and Brodie...they have seemed to have declined in mid thirties. Why should the Leafs fall in that same trap cause a player wants.
Even Pesce who is some of golden boy for Leafs fans seems to have slipped. DeMelo, Walker, Seeler, Tanev would be my four choices with two being future Leafs.

Both carlsson and roy are better than all the defencemen you just mentioned imo. I think we just value the defence position differently. I like to have a dcore that’s hard to play against, im not just looking for competent - not for a cup run

The reason I think Roy isn't signable probably is he going to other options. Being from Michigan, Roy could find a home with two teams that have cap and need a RHD...Sabres and Wings
I might add Montour to the list of possible future Leafs. If Florida feel to it's best to resign Reinhart, maybe Montour becomes. a cap casualty.

Think tre would rather add toughness and defensive skill than another puck mover. But anyway I look at this it always comes back to carlson being the best right handed shot available. And at 4m you leave yourself with enough money to sign another right handed shot like walker or carrier in FA. Thats worth parting with a stud prospect imo. Otherwise youre signing roy or pesce for 6+ and you lose bertuzzi or brodie