updating a previously translated text in Studio

Dear all,

I'd appreciate it if anybody could point me in the right direction on the following issue.
Basically, I have four *.doc documents 
A - an original *.doc in English (of some 37 pages)
B - file A translated
C - file A updated (obviously in English), with the changes concerning around one-fourth of the text (they're indicated with 'track changes')
D - file C cleared of 'tracked changes'
I'm now supposed to update file B to reflect changes indicated in file C, obviously using Studio.
I've aligned files A and B, assuming that at least the three-quarters of the text that have been left intact would be auto-propagated and I'd only translate the rest. Probably due to the complexity of the file with many tables, formulas, etc., this exercise wasn't overly successful, however. When I created a project with file C and used TM based on the alignment of A and B, Studio only recognised 13 percent of the units rightaway and some context matches as I clicked through the text, but this was way short of what I'd expected.
Now, my question is - is there a way to use file B and simply insert my translation (as per file C) in this file in Studio? Or alternatively, what is the usual and most efficient workflow in such situations?
Thank you,
Tomas