It's usually a mistake to try to use Word like any other program

But if
you explain what you are trying to do someone here will be able to suggest a
way to do it. In fact, being Word, there are probably half a dozen ways to
nearly do it, with more or less efficiency!
To get you started, try to define what you (or colleague) mean by "multiple
templates". Do you mean several different page formats - that would be
handled in Word by different sections. Do you mean combining the styles
already present in several different templates? That would probably be done
using the Organizer or possibly by pasting one document into the other.
Reading between the lines, I'm assuming you are trying to combine several
existing documents together - what problems are you having with that? Do
these help:
http://www.shaunakelly.com/word/styles/FormatOfTextChanges.html
http://word.mvps.org/faqs/formatting/PasteWithoutSectionInfo.htm