Unless the Knicks deal Mitchell Robinson, the only way to get help is to look for cheaper alternatives like Keegan Murray.
The Knicks get scoring off the bench in Murray, which they desperately need. Len and Hukporti can fill in for Achiuwa/Sims in the meantime while Robinson makes his return hopefully by the end of January.
Payne is expendable with McBride, Shamet, and Kolek on the roster.
The Kings save 11.1 next year/potential 5th year option. The Kings acquire some draft capital, notably the Washington Wizards protected 1st round pick. It's top 10 protected this season, which is useless this year. It's Top 8 protected next season, then turns into a 2nd round pick if that fails. Obviously next year, the hope is the Wizards, who are primed for another top lottery pick and have around $137 million guaranteed will have the room and talent to be somewhat decent.
Kings would likely pass on this offer, but I think this is an option the Knicks should look into if they want to keep Mitchell Robinson around.