Meghan, you really do need to get out more.

Fruitcakes are made well in advance of the date you want to eat so the flavors have a chance to mix and mingle. "Ripen" is the word bakers use for it. Some fruitcakes, like mine and I would imagine paulhenry's, are "fed" with a few tablespoons of brandy, rum, Amaretto, or some other spirit, every few days or weeks while ripening. The alcohol, which evaporates off (eventually) preserves the cake and helps carry the flavors around within the cake.
Fruitcake should be exempt from your "fruit not mixing with non-sweet stuff" rule , and it can be made without the alcohol.