Having Lehtonen be a healthy scratch would be a massive waste. He could very well be a 1st or 2nd pairing defenceman...

Because the Leafs are TOP heavy by default

With the solid D corp in place long term Leafs should be using assets like Sandin Liljegren Robertson to bring some grit and 3rd/ 4th line forwards that bring a physical edge to the roster

One more piece on that third line would be a reason. Aside from Kerfoot, these are essentially two 4th lines. Giving away 1 defenceman to make room for 1 forward would probably perfectly balance this team out. Still, Sandin and Liljegren are good 7 and 8 options at D so losing 1 will not be that big of an issue.

Because it's a waste of talent. Scratching Lehtonen, Bogosian, Dermott or Holl doesn't make sense. Sandin makes sense to start on the Marlies cuz he's waivers exempt.

finally, someone who gets it

Because you won't have a 4C?

Thornton signed with HCDavos in Switzerland, according to Pierre LeBrun anyway. He's expected to start this weekend for them.

And last I checked no one else will cost that little?

There isn't anything wrong with depth at all.

However, there are a finite number of roster spots and cap dollars available.

Moving depth from one area to shore up shortcomings in other areas also isn't a bad thing.

Lehtonen is interchangeable, I just left him as a scratch because while the hype train is there, we have never seen him play in the NHL. The nice thing about defensive depth is that we can play Bogosion one night against a larger team, and Dermott another. It allows us to actually strategically place d-men into the lineup, rather than being forced to use what we have.

As for Thornton and Davos, he is signing there to get his reps in. If we can't get him, Adam Brooks is definitely a serviceable 4th liner at a similar salary.

The Leafs made a ton of moves to the places that matter.

A 21 man roster is not something the leafs would consider. At least 22

This is a 22 man roster...