There are some things that we should be patient with and there are also times when we need to act decisively or miss opportunities. We need to be patient with Liljegren and Sandin, letting them develop (and keeping them in the org) will be huge for the long term health of our team. Rushing them is a recipe for long term disaster and trading them for a quick fix now would need to be an absolute slam-dunk to make any sense.
But this year is also one of the biggest opportunities that the Leafs will ever have with this core. We have Matthews and Marner on ELC's which gives us the cap space to really load up and try to go deep this year. Patience is important, but we cannot just let opportunities like this pass by. This isn't poker where we can wait for the perfect hand, there will always be other strong teams in the league. We need to take advantage of every edge that we can and ice the best team we can every year. Going all-in would be a mistake, but sitting on our hands and waiting for Liljegren and Sandin is also a mistake.
IMO, we trade our first and some prospects to pick up a high quality D rental for this year. Unless we can find a hockey trade for Gardiner, we keep him as well. That's a significant investment in the team this year, but it's also not raiding the cupboards. Keep Liljegren and Sandin developing, but moves to win today are important.
John Tavares took a discount here because he wants to win. If Matthews, Marner, and Nylander are going to take discounts they want to win. Liljegren and Sandin could be very important pieces for us in the future, but they are not going to help us win today.