It wouldn't be fun for Jersey and their fans...............

Bruh

Yeah... That's not happening.
You're not getting the 2nd overall for 2 aging vets on bad contract and a backup goalie.

You want that pick?
It will cost you either Calgary's or Florida's 1st round pick (if not both), a young D like Romanov or Barron, a young F like Poehling or Ylonen, your top prospect (Guhle) + at least another ok prospect and a roster player on a respectable contract.
Even then, they might not be willing to do it.

They are looking for younger players who can help right now and can grow with the current core if they are trading that pick.
Sending Petry and Gallagher as the main part of your trade isn't doing anything for them, apart from messing up their cap space.

Is this a good offer for a second overall pick: No

That not I would offer to try having the second but is there some value yeah, probably the value are not 100% because of bad years Habs player has in 21-22 but still something to be done.

You say Allen is a backup only and I would argue that he's more a Goalie #1b than simple backup. He had a bad year yeah like 95% of Habs member this season with alot of injuries in total. Is number a still better them a J.Bernier for exemple. 29 / 2.68 / 0.907 it's pretty decent for a "backup" goalie like you say with Habs defense which is not excellent.

Petry is not a top 2 defensemen, he's more a third or fourth defensemen who bring offensive. Put him behind a good first pair duo and he will in the perfect spot for him to play is game. Not so far there was talk about if he could be in a Norris spot but that didn't happen. This season was horrific for multiple reasons.

Gallagher is in the same boat that Petry where the last one have bad years cause external problem the first have been slow by injury. Even with is lots of injury he's still playing the same game style and doing what make him the player he is.

Are they contract big and hard to move ? yeah absolutely but don't mean they can't be trade to the right teams. They always way to neutralize they're big amount by taking back bad contract / involving a third team on a trade to eat cap for pick or lesser prospect etc.

Like I say that not a trade for and second overall pick but don't mean separately or together the player are trash and value nothing at all. Sometimes we need to stop looking at stats and more about what kind of apport the player bring. Experience, Calm, depth or what we call intangible.