Judging with the current rotations, you'd want a second Ray to deal with latios, as it looks like your team could use another one in addition to your maxed one. I'd dump the RC in to ray.
As for the others, it's better to think of future utility. Mewtwo and Groudon will not be challenged but Kyogre will, although it is still stupidly strong to begin with. If I had to pick one, I'd go Mewtwo first, then Groudon, then Kyogre, for rare candy expense.