Halliburton and Hield are obviously the best deal from Philly's point of view.
Curry is a useful player, but he needs to be paired with a bigger playmaker, at least on a major contender, to be a viable starter. McCollum is the best player here, but with Simmons leaving, pairing him with Curry doesn't really work, so that has to be factored into the valuation.
Halliburton provides a playmaker who can cover bigger 2 guards and fits perfectly with Curry, and you add in another elite shooter with Hield. So you are losing some really elite defense, but adding a huge infusion of shooting and not wasting Curry.
I wouldn't trade Halliburton if I were Sacramento, but if they offered this, Philly should take it. McCollum is an elite scorer, but Halliburton and Hield combined provide even more offensive punch and can't be called role players. They are a better fit.