Bad math. You're forgetting to subtract whoever it is that he'll be replacing, for one thing. And there are a few others.
I still do not advocate for trading for a guy that's not going to fit w/I the cap.
He's 36! McCabe comes through the next several years at only $4M. If they're going to give up a 4th or 5th for Johnson, fine, but McCabe is the better player and the better move. EDIT: Please remember that it needn't be a one-off for this season. The team lacks depth on D and we all know it.
At a certain point, he may even have been the Sabres' best defenseman. I've always loved his "special brand of mean," a phrase I used more than once here to describe his play. Get him.
My first thought: It always takes me like four viewings to see what's going on with these because I'm instinctively looking at the puck when I watch on a screen (unlike watching live).
My second thought: It's a two-minute minor and that's it. It's just a routine crosscheck to the back. Maybe a double. MAYBE.
I know a man with a nape tattoo explaining that he is a stroke victim and asking for patience. He points to it when he needs to. Imagine that level of disability, just in a millisecond. It's a nightmare.
I think that McCabe could be the piece the Sabres are missing to get into the playoffs. And his salary isn't exorbitant enough that they'd need Chicago to retain. I'd do it for the 2nd and B-level guy. I'd even give them Vegas's second, which, if the Sabres get McCabe, might be a better pick. Or they can take choice.
For things the Sabres are reportedly "in" on, I suggest separate threads like the current Timo Meier thread. For other stuff, like the present McCabe discussion, I suggest here.