I guess this is where my hang-up is. I don't see a defender in their mid 20's that we could realistically land without dipping into our untouchables significantly. (Maybe Adam Fox?) The D market is so spilt between the young mega stars (Makar, Hughes, Dahlin) and older untouchables (our versions of Werenski) and also rans.
the crucial piece to the "swing big on a defenseman" thing is what, exactly, a superstar defenseman
is at this point. by and large, you're looking at puck-moving offensive defensemen.
we have werenski on the top pair, who is elite. mateychuk looks awesome and will be the main puck mover on the second pair for a long time. and severson, the anchor of a contract that he is, saw the best season of his career come as the main puck-mover on new jersey's third pair.
point being, we have three guys who can drive play offensively, and who appear to be best positioned to do that on three separate pairs. which means the targets defensively should be more rugged, complementary pieces.
we already have one in dante fabbro, who works exceptionally well alongside werenski. we need a short-medium term one for mateychuk (elick could be the long-term answer). and for the third pair, they can either play severson on his off side with gudbranson, get a cheap UFA lefty, or see what daemon hunt can do.
imo: get a lefty PK specialist (not jack johnson) to pair with severson, and a righty shutdown guy to play with mateychuk, then feed those guys
heavy penalty kill minutes and let the puck movers cook at 5v5.
so the assignment here is to swing big on a partner who is tailor-made for mateychuk. i'd argue that the best option there would be mackenzie weegar, but that contract long-term scares me. and the price will be too high on rasmus andersson, who will need a new deal soon anyway.
the rangers and bruins are imploding. both have guys who fit the bill for what we need (carlo, miller) – both would be big swings, but not elias pettersson level swings, and
they have enough assets to do both while still having a good pipeline.
so the question isn't "pettersson OR a defenseman" – it's "pettersson AND which defenseman?"