iMac-Pro(Win 10) NO Ethernet controller Driver (NO BOOTCAMP)
One of the first things I noticed about the article you link to is that there is no mention of a particular model or year Mac. It is impossible for there to be a one size fits all instructions for installing Windows on Mac computers. Second, the article is more than 2 years old. A lot has changed in two years. Any Macs capable of running High Sierra have had a firmware upgrade making many of the articles steps either obsolete or unnecessary.

Here a few comments with regard to the linked article.


I assume you used your iMac Pro to download the Windows Support Software. Using a different Mac can lead to the wrong download.
You do not need to use unetbootin. If fact, you do not even need a USB flash drive.
Starting with with High Sierra, macOS no longer creates Hybrid partitioned drives. So, you should not have to use gdisk.
The article does not mention System Integrity Protection (SIP). You should not have to disable SIP to install Windows.
I assume your installation did not include a Window Recovery Environment partition. I assume this because the article did not provide the necessary steps to create one.
The article included a step where the Windows Support Software (the legacy name is Boot Camp Support Software) is installed. Below is image taken from the article.



Note, there is a folder named WindowsSupport. This is a monumental error. If you have this folder on your flash drive, then I will assume this folder contains the folder named $WinPEDriver$. If so, then none of the Windows Support Software drivers needed properly install Windows were provided to the Windows installation software. If the WindowsSupport folder contains an AutoUnattend.xml file, then the Windows installation software did not receive any addition instructions provided by Apple to correctly install the Windows operating system.

An example of how the files should appear in the root folder of the Windows installation media is shown below. This image was taken from this Apple website. 




You may want to refer the the question: How to install Windows 10 into a 2013 iMac without using the Boot Camp Assistant, USB flash drive or third party tools? The accepted answer provides a few extra steps your article may have omitted.