generate_cover_settings lets you choose both a template of what metadata to use and the regex to compare to. And the first entry that has a regex that matches it's template is the one that will be used. So put more specific above less specific.
Code:
## If you have the Generate Cover plugin installed, you can use the
## generate_cover_settings parameter to intelligently decide which GC
## setting to run. There are three parts 1) a template of which
## metadata part(s) to look at, 2) a regular expression to match the
## template, and 3) the name of the GC setting to use, which must
## match exactly. Use this parameter in [defaults], or by site eg,
## [ficwad.com]
## Make sure to keep at least one space at the start of each line and
## to escape % to %%, if used.
## template => regexp to match => GC Setting to use.
## To use this, make sure you go to the Generate Cover tab in FanFicFare
## config and check 'Allow generate_cover_settings from personal.ini
## to override'
## You can check for an existing cover image in the metadata
## cover_image. cover_image can be:
## specific -- The site has an image that is specifically this story's cover
## first -- The first image in the story or story desc is used as cover
## default -- A default_cover_image was used
## old -- There was already a cover image in the epub.
## This is useful because GC plugin can use the existing image.
# This is a bit simplified, but gets the point across.
generate_cover_settings:
${category},${ships} => Doctor Who,.*Rose/10 => DrWhoRose10Cover
${category} => Doctor Who => DrWhoCover