Think for yourselfer
Yes, it's a policy issue. Disney expects you to be up at 7am 180 days before your vacation to make dining reservations. This is what's creating the issue. This doesn't happen in the normal world, because the normal world doesn't have the type of crazy nonsense going on.I don't think trying to combine reservations is a policy issue though. The policy is quite straight-forward make a reservation and show up or pay $10 if you don't give 24hrs notice to cancel.
It is a guest issue in trying to get more reservations than there are available.
If a local restaurant said we can fit you in at 8am and your friend had a 9am reservation would you say the restaurant has a policy problem when you want to both be seated at the same time? I would say either get the right reservation or try a restaurant that has better availability.
In the normal world I would call the restaurant, ask if they could accommodate us, and if not, pick another restaurant near by. That's not an option at WDW. You are comparing Apples and Pears. Close, but not quite the same.