Plenty here to discuss. I agree that any experienced NHL coach is gonna know the difference between big, slow unskilled and big, quick and skilled -- and will prefer the latter, all things considered. If the choice is between Hedman and Beaulieu, PoMo will go with Hedman all day long.
The problem is that we don't have a Hedman for him to choose anymore, and we aren't getting one. So he has to build his pairings from a mix of PMD talent, size and thee much smaller pool of size + skill available. Under PMD talent we have Pionk, DeMelo, Heinola, JMo and likely Chisholm in the distance. Under size we have Boo and maybe Poolman, plus whomever they bring in as depth. Under size + (some) skill, we have Stanley and likely Samberg, with Kovacevic as depth and Gawanke in the distance.
I'm a longtime booster of Biiiiig Logan -- he's smart, he works hard, he is a sneaky good passer, and when he can get his shot on net he's a sometime threat from the point. But he is nowhere near Heinola, IMO, when it comes to zone exits and entries and the ability to read the play and be a step or two ahead of it. He doesn't have Heinola's deceptive skating and passing, and he has much less of the modern PMD's 4-way mobility. Which is fine -- they have different skillsets for different roles. But I don't think Stanley ever gives you the puck retrieval, distribution and PP quarterbacking that Heinola is already able to do, and I don't think he has Heinola's top-4, maybe even top 2 upside. We've seem Heinola do it at the WJC, we saw him dominate in the AHL, we've seen it on the Jets -- and he'll only get better. In fact, I think he'll be at least as good and likely better as a PMD than JMo in short order. You don't trade that for a Ristolainen, busted-up McCabe, Olesiak, etc.
And being 6' 7'" in a speed-based sport has its disadvantages. Stanley has great reach but his in-tight skating still needs work, because he's got a giant body to move in close spaces -- he was very heavily sheltered this season, playing few to no minutes in close game-states, where the Jets were even, or leading/trailing by a goal, suggesting that they don't yet trust him to be an asset in those situations. Heinola isn't going to suddenly grow 7-8 inches and be able to do all the big D things that Stanley can, but he can gain position on opponents, strip or retrieve the puck and turn it up ice quickly and decisively, minimizing the amount of fire-drill chaos time that we've seen for years now. He brings something that the team really needs and doesn't have, just as Samberg with his blend of size, strength, positioning and calm, also should.
I guess I'm not sure that the big vs small thing is very helpful -- I know this is not the point you're making
@LowLefty -- because if you are controlling the puck in your end you don't really need a core of huge crease-clearers to gain control of it. MTL has some size and grit but they also have a load of forwards who are defensively capable and committed. The Jets def need new pieces there, but another DeMelo or two plus what we have already is likely to be better, I think, than 1 strong and very expensive RHD obtained through the loss of Heinola or Samberg.
The Jets aren't finding another golden-age D corps like they had in 2016-18. But they didn't win the Cup or even the conference then either. So maybe a stronger D made up of 4-5 2nd pairing-quality players, plus a Heinola or ? at the top of his game, and a renewed commitment to strong team defence, will be the next big leap. And while I'd be delighted for a new coaching staff and new systems/structures to be installed to take that team forward, I think you need the players first, then a correct assessment of them and then a suite of systems designed around that personnel.