I'd say ep and sith is still the safest bet. It goes good with traya when you finally get her so it will transition into the next most likely meta. CG has said that a jedi aren't getting an imminent rework so yoda is good to have for the raid and can be used in arena but likely won't be meta any time soon. At least until jedi luke comes out. That will likely be when the meta changes overnight. It takes months of doing the sith raid to 7 star traya but when they release jedi luke many will 7 star him in an event. So along with planning for doing well currently, it doesn't hur to plan ahead. Farm the characters that will likely be needed and characters that will likely work well in the new meta. Cls, R2, Rolo, Captain Han Solo, and Hoda will likely be needed for Jedi Luke and he will likely be good with rebels or jedi. So Raid Han, Cls, Gmy, and Gk are likely Contenders to be in the meta again. But that is speculation. All except that they have said that Jedi Luke will eventually come to the game.