Suggested workflow for frequent directory renames.

Dear git users,

I am working with an externally supplied code tree (some 2000 files, which gets passed to me without any SCM) and have multiple users wokring on their own individual branched versions under git control. The problem I am facing is that there are frequenct directory renames when the code updates which I need to find a relatively painless way of bringing the users branches up to date. From reading the lists and faq, there seems to be problems (and strong opinions) with this, and I am struggling to find an effcient model to manage this merging - either git loses track of the users changed files (and so have to be manually merged from diff files and usually lose history) or git loses track of everything else (and I end up manually adding files from the new tree to get out of merge conflict).

I would be very interested to hear if anyone has a suggestion on how this could best be handled.

Many thanks

Matthew