Sadly, TDP is far from held on those. What you get at 15W is the base clock present at: https://www.anandtech.com/show/15324/amd-ryzen-4000-mobile-a...

For the Ryzen 7 4800U, that's just 1.8GHz. 4.2GHz which is the turbo clock blows through that limit by a lot. (of course that's for multi-core workloads)

For Ryzen 5th generation, we have this for per-core only power draw, without the I/O: https://www.anandtech.com/show/16214/amd-zen-3-ryzen-deep-di...

We can see from the graph at https://images.anandtech.com/doci/16214/PerCore-1-5950X_575p... that to reach 6.6W per core, the clock has to fall to 3.8GHz. At such a clock, Zen 3 is way behind the Apple M1 performance wise.