I started doing Pro/Cabling before the shrinkwrap funtionality existed. I still use the old-school technique of skeleton models. I assemble the skeletom models into the assembly thatI want to use references from, then copy references as needed into the skeletomn model. (feature/data sharing/copy geom)
I suggest making a small "T" part that consists of datum curves and axis that can be assemble in your cabling assembly and referenced only your connector parts and/or FIXed to their 3D location as a junction to route a networkthru. I will be presenting this technique at the Orlando Conference in June 2005.
for my previous presentation see the Routed systems tech committee page on ptcuser.org