For EU you can flash Strategy and Calibration files separately from the rest, but you need to match the versioning on the files and keep them in the fileset Ford released in production. For NA files you need to load all the files at once, and again, keep the fileset.
See this information in relation to the filesets…APIM Firmware Production Releases
Keep in mind the Calibration file will be dependent on region and nav equipped or not.
This also holds true for the APIM software files. Although the files can be loaded separately, it is important to keep the filesets as released for production as this is how they are validated. Mixing older and newer files, especially files for nav, can cause issues with the performance of the APIM, especially so with the older Sync 3.0 versions. Sync 3.2+ seem to be more forgiving in this regard.