No good answer, as they're both scary AF.
Dallas is odd, where when they're at their peak they're the best team in the West, but they're also far more inconsistent than even the Oil.
I do think they caught a break due to the Nichushkin situation, which seemed to wreck COL's focus.
I think COL matches up better against us, as that offence is just scary when on. Though without Nuke they're a lot less scary.
Dallas plays like the Kings on their best days. Which is scary, see game 4 of this year.
Though IMO the Oilers' defence does match up better vs. a team that likes to lean on you with their size and break you down, vs. the Canucks approach of randomly tossing the puck at the net and having it magically pinball in; or COL's overwhelming speed.
The Oil should be grateful they've gotten to practice on how to contain Doughty over the last few playoffs, because Heiskanen brings the same ability to take over the game from the backend.