I read somewhere (tomshardware?) that win11 has features that bring out the best in the ryzen CPUs we've been discussing.
Not sure what you have read but Ryzen cpus work just fine with Win10. I think you may have got a little switched around because it is the Intel cpus with P and E cores that work best with the fancy thread scheduler in Win11.
5600 vs 5600x. Do not get hung up on what frequency and boosts AMD say they achieve, this is just marketing. In reality each cpu will boost as high as it can until it hits certain threshholds. Can mess around in bios settings and would not be able to tell difference between 5600 and 5600x because they are near identical silicon.