http://bugs.winehq.org/show_bug.cgi?id=34122
--- Comment #2 from Michael Casadevall mcasadevall@ubuntu.com 2013-07-23 17:50:53 CDT --- The log was too large to upload even when compressed, so I put it on personal storage space: here: http://people.canonical.com/~mcasadevall/civ5_files_loaddll.log.bz2
There's a fair bit of cruft due to Steam loading, but you can see from the log that Civ5 essentially loads its datafiles in the order located on disk (look for CreateFileW entries for the civ5pkg files).