It's possible that the NBA will allow the draft to take place during the moratorium so deals like the above could take place. It's a weird year. I don't see LAC taking DMDR is an S&T though. I think they'd instead want to trade for him and then extend him or probably not extend him so they could retool in 2021 if need be. Also considering that they'd be a clear tax-paying team, finding a workable amount of salary to send out would be hard. I think Harrell is a good player, but if he's signed to a big enough deal to make the numbers work, I don't think he'd have the value to make this happen.
I could see something of a three-team deal where a team like Philly gets Beverly and gives up their pick to SA. Hopefully that would mean that Richardson is the ballast, but I could totally see them slipping Horford into the deal and somehow coming away with Aldridge or Gay. In that scenario, the Spurs would need at least another first. There are convoluted scenarios where the Spurs could arguably get Minny what they'd want to let SA move up, including maybe getting Minny's own future first back from GS. It doesn't have to be completely different trades, but I think the motivation to get DeRozan where he wants is going to be different from SA trying to maneuver in the draft. In fact, LAC acquiring some salary via trades or by getting picks and signing them to contracts.