The structure starts out ok at the upper levels - where rules exist, but gets more and more bogged down as you dive closer to your department or team's shared folders.
Sometimes, there's absolutely no logic within your department/team folder - it's based on each person's internal logic.
Sometimes, there's too much logic - too many folders to keep going down until you reach the final folder which only houses one document.
This problem of categorical organization isn't limited to business LAN structures, it occurs everywhere humans need to create structure or taxonomies. (That's because there's two types of humans: Groupers and Lumpers. Groupers like to give everything a group whereas Lumpers like to lump everything together into one group.)
Why does this matter and what does it have to do with Tableau?
Well, if you're in a team or department that is sharing workbooks outside of Tableau Server, you've probably thought you could place the workbook in the team's LAN folder and have everyone use it there. Or maybe you don't have Tableau Server and are sharing the workbook with everyone viewing through Tableau Reader. Or maybe you are saving and working on your workbooks from a folder on the LAN.
So what's wrong with that? Nothing, unless they (or you) open it from the LAN. Here's the thing: when you open a Tableau packaged workbook (which is really a zip file), Tableau drops a copy of that zip file on your C:temp folder.
'In Memory' speed - use Extracts and save and work from the folders on your C:drive that Tableau installed when you installed the software. If you're sharing workbooks, tell the other person to save it in their C:drive and then open it. And when you create an extract and it asks you where to save it, save it in the Data Sources folder.
If you don't, then rather than having 'In Memory' speed, you're getting LAN depth * Your network speed and will probably experience lot of 'not responding' or at the least a lot of time watching the spinner and not much time visualizing your data.