I wouldn’t get hung-up on the software being used. Excel files can be formatted to look just like a .doc file with a little work. But it’s not really about the format - it’s about the content.
I know a lot of companies that use Excel as a poor man’s version of MS Project for timelines. The price of MS Project is stupid high ($695). If you know how to build decent formulas in Excel it can be used for a lot of product development spec. and tracking tasks.
The key to developing good specs for China manufacturing is to look into the future and guess what aspects of manufacturing are most prone to screw-ups, then write specs to help reduce the probability of errors. Having said that, sometimes it’s the simple stuff that gets borked.
I have a saying… In China, what should be easy is hard, and what should be hard is easy.