The drivers list in the intel2.jpg is the list of all the Dos drivers that you have to choose from.
When you add a driver to one of the windows pe packages winpe512 in this case then all you have to do is select that version for the preos and all the drivers in it are loaded. It isn't like the old Dos that only loaded one driver at a time.
Some thing that I have found is that the client does not update the copy on the client side after adding a driver and that I had to do these steps to get it to work.
Add the driver to the windows pe in ght GBW
In the console under the properties for the client I had to change to pcdos as the preOS
Then I ran a configuration task so that it would force the update to pcdos files thus clearing out the outdated windows pe.
Then under the properties for the client I would change it back to using windows pe as the preos.
Now the new windows pe will have to be copied to the client rather than using the old stale copy that was already there.
Hope this works for you and hopefully if this is a bug they will get it fixed soon.