Object Copy Rule -> More than one Related Object Rule based on the same property (but with different Keys)

Is this even possible? Cause I always get an error that he doesn't find a copy rule for some object (which is defined in the second "Key")..

So basically it should go through a multi select "Document-Template" Property but should do different things for different document classes (e.g. copy a drawing document which is selected by the user when creating the Object -> File Copy Rules).. 

Problem seems to be, that both related object rules use the same property as source..