I remember it being interesting to work on. It's been years, but if I remember right, there is some way to convince the game to dump a log of unit positions during a multiplayer match, possibly as part of its desync handling. I enabled that on both Win & Linux hosts, ran a match between the machines until they desynced, and diff'd the game's own logs, then confirmed from the Wine logs that the faulty values were coming from CRT-related math functions. It's always fun when you get to use a game's own debug utils to track down a problem.

Anyway it'd be great if the game devs included their own math libraries instead of relying on the OS's. That would fix the problem quite nicely.