And the reason why I believe that package would work is because it's justifiable on both sides.
The Cubs traded Darvish because they're entering a rebuild, but also aren't entirely convinced they won't make one last run because the NL Central sucks. They cleared money, got a solid pitcher in return to keep them in contention with Davies, and increased their prospect capital. Darvish has three years remaining and by the time those three years are up, the Cubs still wouldn't be in position to make a run.
Similarly, Hendricks also has three years remaining. He's less expensive than Darvish and doesn't have the upside, but he's more steady.
So by the same logic, any deal the Angels give the Cubs has to meet the same criteria. They need a major league ready starter in return, and prospects that will put them in position to make another run beginning in 2024 or 2025. Patrick Sandoval meets pitching component, and the upside play of Adams and Jackson together, as well as their ETA being 2023-ish positions them perfectly. And Rengifo gives them another athletic infielder they can use now, or stash in AAA and use later during the rebuild.
On the Angels side of things, he's the steady workhorse, mid rotation starter they need. He's in their price range, and got along well with Joe Maddon, which plays a positive role in the clubhouse and eases the transition. And the Angels are dealing from places of surplus to make it happen. Losing Adams hurts, but with Adell and Marsh in the fold, he's surplus. Same with Jackson, you love the power and athleticism, he might be a star. But with Fletcher in Anaheim, Jones in Salt Lake and a plethora of infielders coming in from the international complex, they can afford sacrificing him. Sandoval is a good pitcher to have, there's definite upside and he has options. But with Barria, Suarez and Naughton already on the 40 man, and guys like Rodriguez and Detmers coming up behind him, and Faria being brought in, he's an arm they can afford to lose. Same with Rengifo. Franklin Barreto made Rengifo a moveable piece for that utility role.