I believe there are several individuals that could land a succesful m&p (mark and pray) timing belt job without the index tools.
For the rest of the mortals the tools will help assure a uneventful timing belt change.
Bonus point: on a PD the torsion value must be adjusted (angular phase of the cam vs the crank). The cam sprocket enlongated holes allow for adjustment when the index tools were used right. If you mis install the cam belt by a tooth or two your adjustment will be off spec... and you will need to remove cambelt re assemble and adjust torsion.
Repeat and rinse.
Use the tools and get it done on the first attempt.
A PD cambelt change is no rocket science if you understand the pronciples, have the correct tools, are competent with them and have the correct procedure. The whole procedure was developed to be pretty much gailsafe if followed correctly.
Ebay tools are better than no tools
Just my humble opinion