No answer from anyone made me suspect there is no performance difference in any way, so I did some test. From a situation where I had about 8 shares but all in the same place, I shared the root folder, and set my Network folders from group policy to go through that, so all my network shares are all accessed through one share, and you know what, there's no noticeable difference at all.
The only difference I found that may give you a reason to not use this approach is the following: Although you can map a networkfolder to a drive letter anywhere down the shared folder, only the share itself has a right-click, map networkdrive option. So if you want to quickly be able to map a network share, then you would want to share that folder directly. Otherwise you can still map a network share, but it is a bit more cumbersome as you would have to navigate to the share first, copy its address, go to This PC, then from the menu create a network mapping and paste the url in there.
From a server managing point, the above is something you actually may want to avoid, and this is a bit of security by obscurity.
In any case, to me the best practice seems to be this:
Try to place all data in one location if you can, and share the root folder. If you have to create multiple shares because the data itself resides on multiple harddisks, then you should name the shares such that they refer to the location internally.
For example, you have a D and E drive, Both have a folder called shares, The Shares folder on D would be shared as
Shares D, whereas the folder on E would be shared as
Now from Group policy you map the shares as follows (example):
\\mydomain.local\Shares D\Share1 -> G: -> Share1
\\mydomain.local\Shares D\Example -> H: -> Example
\\mydomain.local\Shares E\Data -> I: -> Data
\\mydomain.local\Shares E\Finance -> X: -> Finance
To the user, they will just see the names and they get a network drive, but they don't see the actual shares.
If you go to
\\mydomain.local, you will see
Shares D and
Shares E, which will help you determine where the shares are located easily.
Alternatively, you could name the folders
Shares 1 and
Shares 2, and share them the same, if you want to hide the physical location. Another approach, is to come up with a name that starts with the letter of the drive. For example
Shares Daisy and
Shares Elvin Gadd