You seem to be arguing that it's within the realm of possibility to trade away all our depth, and sign a $10 mill aav defenseman, and then have 60% of our cap tied up on 5 players.
Sure.
That's within the realm of possibility.
But it's not practical.
I would love for you to show me a way (that makes the team better) that the leafs can sign an approx $10 mil superstar ufa defenseman, keep the big 4, and fill out the rest of the lineup.
I would love to see it.
Not sure how you are unloading Nylander for that $10 mil UFA Defenceman in the first place.
But, basically do exactly your plan for trading Nylander to get that defenceman, clearing 6.9 mil.
Instead of trading Nylander to open up the 6.9 mil, trade 2 of Johnsson/Kapanen/Kerfoot.
If you assume the 4th line stays similar.
Current Lineup:
Hyman - Matthews - Marner
Engvall - Tavares - Nylander
Johnsson - Kerfoot - Kapanen
Timnashov - Spezza - Goat (Or equivalent cheap players)
That 3rd line would lose 2 players who are replaced with 2 of the following:
Brooks, Moore, Mikheyev, Bracco, Petan, Marchment, Agostino, Wilson (if he resigned) etc.
The teams biggest need is D, so doing this IMO does make the team better, the 3rd line isn't exactly lighting the league on fire.
This is just one route also, there could me infinitely more possibilities, as I have said multiple times.
Edit: added word "mil" in first line before someone comes up with the "hilarious" joke that a D would be worth $10