I wasn't thinking straight last night. The right way to do this is with list_equals, not list_sort(). This way neither the order nor the spacing matters.
Code:
program:
f = $#fanficcat;
if list_equals(
f, ',',
'Crossover, Mass Effect Trilogy, Mass Effect: Andromeda', ',',
'1', '')
then
f = 'Mass Effect Trilogy, Mass Effect: Andromeda'
fi;
f