I do not have the global so I am not sure how it is structured in the scenery list, but since it is texture and should not effect anything else, I would try it both below and then above and see what looks the best with whatever California scenery you already have. If the scenery has photo real the global will not be seen regardless of the priority, keep in mind. Also as a point, move the Cal scenery as the ORBX stuff will just put itself back were it was again after the next update.
Dave