I also don't think that my cultivation (including the “The Alps” cultivation) and the ORBX cultivation can be used together at the same time, because the area coverage of ORBX differs from the grid system of FS2. So even deleting some areas you still will have probably overlays and missing areas on the over hand.
What is easy to do an I reccomend is to switch between the two cultivations (you dont have to delete them):
Just rename the cultivation-folder with two underscores from "orbx_switzerland_cultivation" to "__orbx_switzerland_cultivation" to deactivate it. Proceed in reverse way to deactivate my cultivation.