My outside sense on the Grizzlies is that if the Kings or Hawks take JJJ or someone other than Bagley or Doncic, they may deal the pick, but if either Doncic or Bagley are there at 4, that is their pick.
From my understanding, Parsons is definitely on the trade block, but the feeling is the Grizzlies didn't spend most of last season "developing young talent" to draft too far down the first round, especially since the way the salary cap works, dealing Parsons doesn't open up that much to spend.
I have heard the rumor of Grizzlies #4 & Parsons for Bulls #7 & #22 (and whatever parts are needed to make the trade work, like Portis), but that was an online source, and Pippen Ain't Easy. The matching of salaries makes this difficult.
The player that matches salaries with Parsons best is obviously Harrison Barnes (but Matthews works). I can't imagine why Dallas would trade Barnes & #5 for Parsons & #4.
I don't count out #4 + Parsons, for Harrison Barnes.