http://bugs.winehq.org/show_bug.cgi?id=31113
--- Comment #92 from Michael Casadevall mcasadevall@ubuntu.com 2013-07-28 03:27:17 CDT --- So I have confirmed that the underlying cause of the data file errors is due to the load order of the civ5pkg files on startup (which also break BNW). Unfortnately, due to the APIs being involved being extremely core to WINE combined with the fact that this app only works due to luck (its taking advantage of a quirk in Windows that is only true some of the time), there is no real way to patch this.
Without a shim layer in WINE that allows us to selectively apply patches to apps, there's no way this can be fixed.
That being said, I've managed to modify a FUSE module in a way that will cause the datafiles to load correctly (essentially rewriting readdir and making it return files in the proper order).
My code is a bit hacky, but it works, and I've managed to set it up on two machines, and play several SP and MP matches to completion. I'll try and get a writeup done tonight or tomorrow.