If you have more than one player on a part they will self-organize to stagger their breaths. And no-one is going to die to make it without breathing. You don't have to necessarily provide a rest or a breath mark. Part of being a good musician is figuring out the best pieces to breathe to make individual phrases out of a piece of music. It's part of what makes music sound musical. Part of being a good director is over-ruling those decisions and suggesting other solutions if something is standing out of the overall mix, since they are sitting where they can hear the interplay of all parts more equally. I wouldn't stress over it too much.