Unsane, Page 5, clause c of your doc is especially interesting. It seems like the right way to go about it is for me to go with my wife together to the embassy; I would get a TN visa, which then confers the derivative TD visa on my wife. I was originally planning for my wife to go there alone with my job offer letter, but that probably makes her look more like the hundreds of individual applications that they receive everyday.
There was an earlier thread in which the poster got himself a TN and his wife a TD in vietnam.
The clause in question is:
"One instance in which a Canadian would apply for a TN visa: a Canadian
without TN status, who resides in a third country with a non-Canadian
spouse or family member, and who is planning to enter the United States
as a NAFTA professional with his family member(s), will need a TN visa in
order to confer derivative TD status on his or her dependents. In such
cases, the Canadian citizen could not wait to have his or her case
adjudicated by the Department of Homeland Security (DHS) at a port of
entry (POE), since the non-Canadian dependent(s) would require a visa to
board a flight and to apply for entry into the United States."