Also after last post I found this website --from March 2019-- that some how assists in doing what your sugggesting.
This tutorial shows you how to create Windows 10 bootable USB from ISO on Mac, by using the Terminal or third-party software like UNetbottin.
Actually, it may be easier with the MAC, as you may be taken directly to the ISO download page.
To download an ISO on Firefox, go to https://www.microsoft.com/en-us/software-download/windows10
then press the shift, ctrl and "M" keys simultaneously. Refresh the page using the refresh circle in the upper left corner, left-click once in the center window, then use the down arrow key to find "Select Edition". You may be better off with October 2018 update, considering the problems you are having with 1903.