It’s worth reiterating what I think is your underlying point- improving 3rd pairing to reduce burden on Parayko-Miko could have similar impact as upgrading from Miko on that pairing.
That is
absolutely my underlying line of thought.
If you can't upgrade Mikkola, then make the 3rd pair good enough that they can
effectively take on much of the burden Mikkola-Parayko are currently shouldering. Right now Mikkola/Parayko are handling a top 5-10 hardest workload in the league. They are being deployed like an elite shutdown pair. Krug-Faulk are being deployed like a sheltered 2nd pair and then the 3rd pair is being used as an average 3rd pair.
One way to address the defensive issues is to upgrade Parayko's partner to a guy who's good enough to be half of a true elite shutdown pair (The J-Bo role in 2019). The Krug-Faulk pairing keeps the same deployment and then the 3rd pair becomes Mikkola-Bortz (or a rotation between those 2 and Scandella if you can keep him). That 3rd pair either keeps the same usage or potentially takes a smidge of Parayko's hard minutes. The overall usage stays largely the same, but Parayko's partner allows that pair to do the job vs elite lines more effectively.
Another way is to bring in that same caliber LHD upgrade, but spread the wealth a bit. Put the new guy with Faulk and give that pair some of the hard minutes Parayko is currently eating. This means Mikkola-Parayko aren't being asked to do as much and should theoretically have better results. Then Krug-Bortz (or potentiall Scandella) gets very easy minutes and Krug gets to rip apart even easier competition.
I prefer both of those options to getting a RHD, but my concept is that getting a LHD upgrade isn't the sole way to take some burden off Parayko to make the whole unit better. If the 3rd pair is suddenly a legit 2nd pair-caliber unit, then you can better set up every pair for success.
We're asking too much of Parayko and way too much of Mikkola. The playoff path is loaded with elite top lines. Calgary, Minnesota, and Colorado each have a genuine claim that their top line is top 5 in the league. We haven't seen them together, but it is reasonable to believe that a Patches-Eichel-Stone line could join that conversation. Getting out of the West is only going to happen if we can shut down 2 or maybe even 3 truly elite top lines. I don't believe that Mikkola-Parayko are capable of doing that and that isn't a knock on them. If you can't rely on either of your other pairs to reliably shut down elite lines (which we haven't seen any proof of concept for at this point), then consistently getting that 1 shut down pair out there against that top line means that both guys on the pair have to be able to give you 24+ minutes of his A game every night.
I think Parayko is capable of doing it if his partner is a top/middle pair tweener. Mikkola is not, which is 100% to be expected for a guy that isn't a seasoned NHL vet or complete phenom. If we can't get such a guy to carry that burden with Parayko, then our only option to shut down elite top lines repeatedly is to spread that burden between two pairings. If we have two pairings that you feel comfortable having out there against that top line, then you can dictate the game without asking too much of Mikkola and/or Scandella. Again, ideally we get a LHD already comfortable and effective getting 23 minutes a night in all situations that can take on that burden with Parayko. But if not, getting such a guy who hapens to be right handed would at least have a similar impact to the group (albeit with a very different type of deployment).
Imagine a world where Lindholm is extended, Arizona/Philly/Columbus bide their time barring a wild overpay, Gio is suddenly the only top 4 LHD really on the market and Seattle demands a 1st and Perunovich. It's not the most likely scenario, but it is a realistic turn the market could take. We could also get to Gio as the last option if a couple teams meet asking prices on the players like Chychrun/Lindholm/Sanheim. If we reach that point, I'd rather start kicking the tires on Severson than sell multiple assets to rent Gio.