Earlier quoted context omitted.
Another option I recommend comparing two Word docs (and just about anything) is Beyond Compare.[0] It's the software you would have to buy, but if you have to compare files a lot I would highly recommend it. (Runs on multiple platforms, too.) [0]: https://www.scootersoftware.com
WinMerge does the same, and it's open source. It's only for Windows, though. http://winmerge.org/
Aside from multi platform, BC has things like CSV compare and marking unimportant changes are fairly robust. I do personally prefer open source myself, but BC is certainly one of the few that I didn't mind paying for.