source of documents embedded in SL

When you publish, SL loads the document, and makes it a permanent static part of the published package. It will then be available through the Resources tab. Or if you want the learner to access it clicking on a link on the slide, follow the above mentioned article. So wherever you send the published content, the resource file is part of it. You will be happier, then if the document is on your local hard drive.

If you are using the document as a web object, it's a different story. A web object is a file that is external to your published content. It is useful if the original content is not under your control, or if you want to change the content without having to republish the course. To use a file as a web object, it has to be available over a network (usually the internet) to the learner. In that case, you neither can nor should want to use a local drive. Probably SharePoint is your best option, but the learner must have access to the file.