Assuming the Pacers move one this season, which one goes depends on what the Pacers want back.
1. Stephenson can probably bring in the biggest return like Rondo along with draft picks.
2. Stephenson can also bring in Jennings or maybe Holiday along with draft picks.
3. Granger will have an expiring contract that will be an huge asset. But, that probably only brings back draft picks in a weak draft.
The Pacers respectively could trade Stephenson this year and move Granger for picks next year. It all depends on what's best for the team.