Technically if you were to get 3200, it would first run at the boards native frequency, which is usually 2133. Then you would enable XMP, which is a form of overclocking, to take it up to its rated speed.
You can then overclock beyond this, but that's where your likelihood for instability increases, and you have to be more careful as you're taking it out of manufacturer's specification.
You can adjust CAS latency accordingly, it's just a balancing act to work out what is stable.
A full and better guide is here:
https://www.tomshardware.co.uk/ram-overclocking-guide,review-33633-3.html
Personally, I think it's easier to simply get RAM that's rated to the speed you want to achieve.