Can't say yet about Orlov? Have you watched him at all? He's making the same type of mistakes that you called Green a nitwit for, only even more frequently.
Burakovsky is probably the next worst offender in terms of terrible, dumb, inexcusable turnovers. He had one play on Monday where he fired a random, no-look one-touch pass at his own blueline, keeping the puck in his own zone. It's the type of play that would be lauded if he was a defenseman for the other team. And that's hardly the only time he's made massively risky plays with little potential for reward. Hopefully it's that he's young, but it's not an encouraging sign about his hockey sense.
Chimera is completely lost any time the play isn't "cycle endlessly" or "streak down the wing and crash the net in transition." He does his job effectively, but his job tends to be remarkably simple. Watching him try to gel with Kuznetsov last post-season was pretty hilarious. When Kuzy hit him in stride in transition it was great, but any time Kuzy tried to set up a prolonged offensive zone possession, Chimera was like a deer in headlights.
Wilson is similar to Chimera, though less effective and with more dimwit penalties. He used to be a cruise missile on the forecheck, but he was pretty much a puck chaser. He's been neutered lately, but it's not like he's replaced that forecheck tenacity with a newfound ability to read plays. And as I said before, dimwit penalties. Leading the league in penalties taken is not something to be proud of, even if some of them are reputation calls.
Weber is just atrocious in his ability to read plays and gap up properly. Not sure why you think he may be smart. Not sure what you're holding out for with Latta, either.
Ovie is massively talented and the team is immensely lucky to have him, but he's not a particularly smart hockey player. Watching him struggle through his slumps is pretty much proof of that, as he keeps trying the same things over and over again to no avail. How many times have you watched him skate in 1-on-3? Try the same move against defensemen that they learned to cover in 2011? Be completely out of position in the defensive zone?
I also think you overrate the hockey smarts of Oshie, Niskanen, and Orpik. They aren't dumb players, but they aren't particularly smart ones either. They also lost one of their smarter players in Joel Ward (albeit, replacing him with Williams is an upgrade in almost every department, including hockey IQ). This team still has plenty of dumb players, and I certainly don't see any trend away from that.