The important issues is the security. The pages should not be open to the public.
Get around that by hosting the site on your internal LAN and then nobody outside the company will have access. Another option would be to password protect the directories where the the wiki is installed.
DokuWiki has Access Level Controls so that you can limit access to content. [dokuwiki.org...] I'm not sure if that is easy to maintain for a large number of members though.