When the "Who owns this PC?" screen does not show up, I have the "Create local user account" screen, so I never have an account name with garbled letters.
Think that we are on to something with this statement. The end result it the same with either question. What is the common denominator?
One would think "Who owns this PC?" would come up if system was offline, while "Create local user account" would come up if the computer was online because now it wants to set up a local user account.
Now we know that could not be the case as you mentioned that these are all desktops, so I must assume that they are all hardwired for internet access.