It's subjective takes on this - but I fail to reasonably assess that NHL-caliber defensemen...let alone all-star caliber defensemen cannot play the other side of the ice.
However- I guess my bigger point is that when your star players take discounts - spend them where it matters. With the exception of McGinn's recent run, the difference between 3M bottom-6 players and 800k bottom-6 players is marginal. But the difference between a 5M 3rd pairing (possibly first pairing) D and an 800k D is tremendous. You could REALLY balance minutes.
It's not even that you have to trim your entire offense to accomplish this. You could work on a trade with Dumo+, backfill dumo with POJ/Petts, etc. You'd be adding +4-5M on D and looking to subtract that somewhere. Kappy would represent 3 of that with demonstrated backfill. You just have to find the other 2. San Jose needs someone like Blueger - but that's just 1 option.
For the sake of discussion, I'm going to push back on a couple of things here.
1. I don't believe Letang nor Malkin really took "discounts". I think their contracts were very fair for 35+ and getting the term they did.
2. The savings on those lowered cap hits are what allowed us to take in Petry and resign Rust and Rakell. Looking at the Top 6, we have 4 bonafide Top 6 wings. We couldn't do that if we were missing $4-5mil in space being taken up by more expensive Malkin and Letang deals. I would maybe suggest that Rust took a bit of a discount. But yeah, we used those saving appropriately, IMHO.
3. I think paying the opposite side and playing it as well are two different things. I think it's pretty rare to see a guy truly capable of equal play on both sides. Their shooting side and the judgment they've been able to hone over a career will be different. Sure, a guy like Rudwedel or Freidman could easily hop each side, but neither is at the level of Letang or Karlsson, or even Petry. You get good at those positions because you have a level of consistency, and you develop your play (both physically and mentally) around that.
I'm certainly not saying they can't but Karlsson is an $11.5mil guy at RD. He's played RD for the entirety of his career. Same with Letang and Petry. I'm merely suggesting that switching sides may be more difficult than you think when you get to that level. What would Sid be like at wing? He could certainly play it, but would he be as effective?
4. Balancing minutes is important yes but sometimes the level of play a guy like Letang, Karlsson, or Petry is able to provide is due to the minutes they play. Good example - Brassard. He was a quality 2C for Ottawa as he was playing 17-20min a night. He comes here for the 3C role, gets bumped to 13-14min/night and he turns to trash as does his production. He even commented on that after he had been sent out.
You bring guys like Letang, Karlsson, and Petry in because you want and need them to play big minutes. Would we bring in a $5-6mil guy to play on the 4th line? Wouldn't make much sense.
That all said - Dumo+Kap out and Karlsson in...well now you wouldn't have to twist my arm that hard. I might even enjoy that kind of pain and ask you for more.