Both the A and C can share cars, whether it's the r179's, or the r46s. I don't think anyone is questioning
The important thing is, like I mentioned before, that the 12 10 car r179's go to the A/C, the 8 car NTT'S as well as the r32s go to the G, while the displaced r68s go to the B.
I know a lot of commuters in the Bronx, Manhattan and Brooklyn will be very happy if this scenario happens.