More a case of having a working word processor & there's no way the company is going to pay hundreds of dollars for more software hence make Word work. As it was the previous iterations of manuals used Word as little more than a glorified typewriter and barely touched some of the automation features available.
If I had the time available I think I'd rather establish all the manuals within a CVS system to manage & track changes and only checkout the manual for compilation & printing when needed.