Randle is the heart and soul of the team, way to dangerous to trade him in season. There's a very real possibility it could sink the season, regardless of who comes over. A traded guy can't step into a leadership position mid season.
I think the starters are better with IQ rather than RJ. With RJ out there the 3 point shooting is way too unsteady. I don't know if there's an easy way out of this problem. RJ's contract is difficult to trade, I don't think the Knicks are interested, they already had a deal for Donovan Mitchell on the table this summer and decided to hold on to him.
I think the Knicks best asset is their FRP for this summer. The possibility of the Knicks crapping out for the rest of the season is pretty high, they have one of the harder remaining schedules left. You have to figure there's something like 3% odds the Knicks pick moves up in the lottery at this point. I don't think that will happen but realistically, it's possible.
Knicks have a lot of semi dead salary in D Rose and Fournier to make deals.
I would do Fournier Hart and Reddish and 2023 unprotected FRP for Rozier and Plumlee.
Plumlee can hold the fort for Robinson for the next month, apnd then adds a different dimension for when Robinson comes back. Rozier can start with Brunson and Grimes and then RJ and IQ can wreck teams from the bench. The new Knicks are just good enough to get the 6 seed and just bad enough to possibly get in the lottery.