I assume you just don't know that much about Winnipeg. Like the Wings, they are kind of loaded with mid-level forwards: Wheeler, Scheifele, Little, Perreault, Ehlers, Stafford. Obviously Laine will be in the mix. Most seem to expect Kyle Connor to make the team and some think he may be better than Larkin. Just signed Matthias. Dano looked ok for them last year. Burmistrov will probably never amount to much, but he's still only 24 so I doubt they've completely given up on him.
I'd say it's hardly a lock that Sheahan or Pulk would even make their top-9, much less top-6. Plus they (like pretty much everyone) are already going to be struggling with the question of whom to protect. Then you include Smith, and either they resign him and have to protect him, or they risk losing him as an UFA.
The Jets offense wasn't very good, but neither was their defense. Even losing Ladd, the potential impact of Laine and Connor plus continued development of Ehlers (and maybe a little more from Scheifele even) gives reason for some optimism there. On defense, Morrissey is the only good prospect they have. Getting rid of Trouba for anything other than a direct replacement doesn't make much sense. Maybe for a real upgrade at forward or a top pick + prospect that wouldn't need protection.
Really nothing about that trade makes any sense for the Jets. The only way it would is if they get completely desperate with being unable to resign Trouba, and just go for the highest bid. But you already admit that wouldn't likely be us.
The Anaheim deal is a bit better, if you presume they are still looking for help at forward. I'm not sure they still are, but they do have a lot of good young D. Not so sure Nyquist + Holmstrom would get Fowler (E and Bieksa is more or less a wash), with Nyquist coming off a down year and with a longish-term contract. Also not sure Fowler is even good enough to be worth Nyquist.