You do realize that ram speeds of transmission are counted using nano-seconds. The difference realistically between 3200MHz and 3600MHz, assuming the same timings, would be a couple of minutes on an hour long render. Etc.
The reason why 3600MHz is the touted 'sweet spot' (it really isn't, 3733MHz is) is because it's the fastest and most readily available ram that still maintains a 1:1:1 ratio in the infinity fabric. Beyond 3733MHz, it switches to a 1:2:1 ratio and gets slower. Same thing with 2000 series cpus, but that limit is 3466MHz, making 3200MHz the 'sweet spot'. The only reason 3466/3733 isn't the popular choice is because it's all too easy to see changes in BCLK, FSB, ram settings etc which can make it into 3734MHz and games will show that with speedups/slow downs on screen fps. Better to be solidly 3600 than variably 3733.
Stand on the side of a freeway. 2 cars go past you. One is doing 95mph, and one is doing 100mph. Tell me whether the red or the blue car was faster. You can't. You cannot discern that small of a difference. It'd take a cop with a radar gun. Or a benchmark, if you will.