Perhaps a little clearer....
BigB example is 14/2NM, but he said 25 amp OCP, using the nameplate max figure.
Using the max OCP, a #12 EGC would be required, so using NM he has to use 12/2.
Yes, the EGC does not have to be larger than the circuit conductors, 'oversize' EGC to my knowledge is not available.
IMHO, I believe that he did not read Table 250.122 where the amperage col. jumps from 20 amps for #12, and 60 amps for #10.
