What if I buy 3600mhz but I'll decrease the speed through the bios?It's not supported on your motherboard, https://www.msi.com/Motherboard/support/B450-TOMAHAWK#support-mem-14 there is always the silicon lottery - it might or might not work :-(
So, you're advise me to get the 3200?The F4-3200C14D-16GTZN Trident Z Neo RAM kit is b-die so hopefully should work but you might not get the maximum frequency if you get the 3600 version F4-3600C14D-16GTZN, F4-3600C14D-16GTZNB etc. As the motherboard QVL goes up to an approx. maximum of 3333 MHz you won't find any RAM kits tested at 3600.
The motherboard supports b-die as https://www.gskill.com/product/165/...ZDDR4-3200MHz-CL14-14-14-34-1.35V64GB-(8x8GB) looks like b-die and is found on the QVL as F4-3200C14Q2-64GTZ. 3200 CL14 kits I would guess are all likely b-die.
So, you're advise me to get the 3200?