Just to note, I wasn't bringing up player points 4 games into the season. Another contributor mentioned Kerfoot having more points than Kadri, so I brought up Gardiner. I don't think any stats 4 games into a season are all that relevant.
But over the course of the season, I don't think Muzzin is much if at all better than Gardiner. We had both guys last season and they couldn't get us past Boston. Although to be fair, Gardiner was crippled and Muzzin was fully healthy.
For me, I would prefer Gardiner long term at a reasonable number plus 3 young assets over Muzzin for one more playoff run or Muzzin long term at what will likely be a number hard to swallow.
There's also now the issue that if you keep Muzzin long term, it's likely impossible to keep Barrie long term, and he cost us one of the best value centers in the league.
Again this is why I find the series of moves to be very odd and not well thought out.
Muzzin and Gardiner are completely different types of defencemen. You likely don't even get to Game 7 last year without Jake Muzzin. The Leafs desparately needed a guy who can play heavy in their top 4. Overall, they might be similar calibre defencemen, but the fit is much different.
As for the long term thinking... I think the Leafs were faced with a couple realities.
#1. A group comprised of Rielly, Gardiner, Zaitsev, and Hainsey/replacement was simply not going to get them deep into the playoffs. They needed Muzzin as a physical presence to add to the top 4.
#2. With Muzzin in, they needed a Hainsey replacement, and either a Gardiner replacement or Gardiner back. Barrie is a substantial upgrade on Gardiner, and costs us substantially less this year. At the end of the day, gettting Barrie for 1 year meant downgrading Kadri to Kerfoot for the next 3-4. Is it a great deal? no, but if your focus is on making this team more complete and trying to win a cup, then it's not a bad deal either.
Were there better deals out there? obviously we don't know. Getting Pietrangelo when St. Louis was near the bottom of the league would have been better... but we really haven't seen any defencemen change hands that are objectively better fits than Muzzin or Barrie.