Here's the thing about Grant as opposed to Barnes, Grant actually has a history of doing close to it whereas Barnes hasn't. Barnes in iso in a vacuum is >>>> Grant, but no team has appeared to be willing to give Barnes that including the Kings and from what it looks like it's because Barnes won't accept the offer.
Even if Monk walks this summer (ugh), you found your diamond in the rough in Keon while Keegan is primed for a massive year 3 breakout with his year 2 growth. Hell, even Davion rose from the ashes and was a super valuable rotation player like the last 3 months of the year. No reason he can't build on that as well. Colby Jones showed you some flashes and pick 13 should hopefully be a useful future asset as well. That's a decent future to invest in.
If Monk walks, I think you absolutely have to repurpose Huerter/HB into something and just invest in that youth popping around Fox and Domas. Maybe you actually think about a Huerter+HB for Grant+draft picks swap, that opens real opportunity for these guys to pop: