The MSI Tomahawk boards are pretty solid boards that even suport some overclocking although i said that with the 3600X i would just leave that alone. The X470 might have a little better vrm and has alittle better audiocodec 1220A vs ALC 892. The chip for the lan might be just abit better too.
Both do well when it comes to fan headers,both 6 of them.
It's up to you,if you know someone who can update that Asus motherboard for you see i no reason not to go for that one. Chose the MSI for it's usb bios flashback and that afiak it's a stable motherboard with still good features for it's price.
Having said that with what the Asus costs are you so close to getting a board with a X570 xhipset that such a board is probably preferred.
MSI B450 TOMAHAWK ATX AM4 Motherboard vs. ASRock X570 Pro4 ATX AM4 Motherboard vs. ASRock X570 Steel Legend ATX AM4 Motherboard - PCPartPicker
a few tenners extra,but i do like the "Steel Legend" in that list.
The difference in gap is the smaller ssd,i chose the 250gb Kingston NVME for bootdrive where you chose a Samsung sata disc which is almost twice the price.