That's probably true, but there are a lot of advantages to using the donor wiring harness and PDC/fuse panel. Your starter/solenoid and alternator wiring is in the PDC and harness. But, the biggest advantage is you can rewire your lights and fuel pump through the PDC panel utilizing the power relays. I also made my own ignition switch power harness to do away with the original mega splice under the dash.
The biggest advantage to using the donor harness and PDC is it puts your fuse panel in a very accessible location. We old farts don't have to get down and stand on our heads to get to the original a-body fuse panel. That's worth the extra effort!