I don't think thats even possible, as the A/M silicon is specifically designed/fabbed for lower clockspeeds.
That is like saying every single Intel CPU cant be overclocked because they were not designed to do so. There certainly is a limit ( It definitely cant do 5Ghz ), but I am willing bet a 20% is easily achievable with enough cooling.
Maybe one could get f_clock a bit higher, but what would be the point comparing an overclocked CPU with one working at normal frequency?
The A17 is already on the TSMC 3nm process, while the 7950X is on TSMC 4nm. If anything, the A17 has the advantage here and the real question is, where the AMD chip would land if it was produced with the same technology.
I'm sorry, the original post was about the 7640U, which is indeed on 4nm.