I'm still surprised they haven't "traded/offered" CSN-NW for Root-NW, and CSN-Phily for Root-Pittsburgh.
If you followed the dispute from a couple years ago, you'd know that what you suggest wasn't possible. There were eight networks involved in total - FSN Pitt, FSN RM, FSN NW, CSN NW, CSN CA, CSN BA, CSN Chi, and Versus (which was yanked for ~6 months). Note that CSN Philly is not on the list, because that one was locked away and untouchable. Also note that there are five Comcast-owned channels on the list, with only three owned by DirecTV. If they did one-to-one swaps, they'd lose out on two of the Comcast channels.
Ultimately, DirecTV ended up having to concede CSN NW in order to reach agreements for the other networks and restore Versus.