Acquiring all 4 would be impossible. 3 would probably be a stretch. We just don't have that many tradeable assets. Then there's the fact that two of the trade partners are current division rivals and the other two will be next year. Also cuts very close to the cap, and could potentially cause trouble the year after next when Datsyuk, Ericsson, and Quincey need to be re-signed or replaced.
Fun to fantasize about and on paper it might look great, but there's only so much ice time to go around. All those guys aren't going to match or better their career highs, some may not fit in at all, and most importantly I think is that it just ignores the real problem: Datsyuk and Zetterberg.
Prior to the last 7 games, we were averaging just under 3 gpg. That's boosted a bit by the big game against Vancouver, but even if you replace that game with a "normal" good game (say 4-5 goals), it's still around 2.75. Not great, but not too bad considering we've had at least one top six forward out for over half the year, and none of White, Quincey, or Smith are producing any offense.
We've scored 10 goals in the last 7 games, and Pav and Hank have combined for just 5 points. Hank has 1 goal in 19 games. Any team is going to struggle scoring when their stars are slumping at the same time. Surrounding them with 2nd-tier scorers (with 2nd-tier salaries) won't necessarily help as much as you might think, as those players usually depend on the stars to get their production.
Overall, Pav and Hank are still having a good year, and I expect they'll turn it around soon enough. The real worry comes in the future. If already we're seeing slumps like this (and the start of last season), what will happen in 2-3 years? If they continue to decline, and this becomes more the norm, then players like those listed aren't going to help. Or at least, not make us a contender. Just the opposite actually. We'll be fighting the cap, most/all of those guys will have much lower trade value, we'd have given up our entire next generation to get them, and likely stuck in a mediocrity trap where were too good to land a top pick but not good enough to do anything meaningful.
Instead of 4 complimentary players, what we really need is a 3rd star. Someone to ease the pressure on Pav and Hank, and young and good enough to assume the lead when they decline. Complimetary roles are best filled with cheaper kids and vets, and maybe a couple in their prime. Unfortunately, the prospects for getting another star aren't good. Failing that, stockpiling picks and prospects is the best bet. It's a more certain, and likely deeper, decline; but the recovery should come quicker and be more lasting. Adding one of those guys would be alright, if the price was cheap.