This is an impossible question. I'd generally say, flowering shrub in more sun, but they both flower. Evergreen in more summer shade, but you can get lost trying to finesse things to ultimate perfection with little real advantage. If the hydrangeas do well for you in coastal carolina, i'd have to think the camellia would do well in similar conditions. Beyond that, look around you. Find confitions similar to yours. Do these plants co exist in established landscapes around you? If yes, you have your answer. If no, you may have your answer, or you may want to find out why.