We have about 100 users and one way we found to control things a little better was to break down the users based on their current functions. When we did this we had approx. 4 groups of 25 users each.
There are certain files that are used by all 4 groups, these files are placed in a common location for all, but strictly maintained by 3 people. In another area, we have the files that are common to each group since each group has their own separate menus, lisp/vba, standards, blocks, etc that is specific to their discipline.
In addition to that we have management support that initiated the enforcement of things, and later (with a document management system) users enforced things on there own.
We allow users certain abilities to customize their environment without infringing on the dept processes and procedures. However we do not use one standard pgp file. We found that people were more productive when their hotkeys made sense to them, and the end result is the same regardless of what you call it. We do control the Autocad pathing and use a bottom up approach such as:
User files - User lisp, pgp
Section/Unit files - menus, blocks, acad.lsp, lisp/vba
Department files - Standards, templates/master plates, manufacturer drawings
General Use files - Title blocks, borders, lisp/vba (generic)
Also just as a side note, Educate your managers! Get them on your side! For them to be able to support you in your efforts they need to understand the problem. Be as detailed as you need to be without confusing them (you may need to gage this based on their interest/concern).