Did this change recently? I haven't played in a month or so but it's been working great for around a year now for me.
At some point, Proton users reported success using some patch, then that stopped working, then there was a different patch... A lot of user reports say "thumbs up" then have a comment explaining how it goes out-of-sync unless you fiddle with it, so it's hard to trust.
Seems the root of the problem is this game's picky netcode, which is similar to the original 1998 game I played as a kid. If your game state diverges from the other players' at all, it goes oos and ends the game for everyone. And yes this happened often enough that people had an abbreviation for it.
Oos can till happen, but as you said it can also happen on Windows, hard to blame Wine for that.
Since gold means "works as good as Windows with workarounds" I think that's a correct rating.
Also, "gold" should mean that it works by default, not that you have to patch in a DLL. The only place the site even says "playable with tweaks" is in a tooltip if you hover over the gold symbol, right above a separate list of details that doesn't mention tweaks. I didn't even know until now.
We can argue all day over what a rating means, but if it would work without a tweak I'd say it should be rated platinum. (The only other thing I know is missing is Xbox live login, but I don't really care about that)
That was as far as I was able to take it. Another much more skilled dev at CW dug in a lot deeper and wrote a blog post about it[1], but as far as I know the problem remains unsolved.
[1] https://www.codeweavers.com/blog/rbernon/2022/9/12/ucrtcring...
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.
For a practical solution, just using the Windows dlls seems to work fine. Without AoE2:DE goes out of sync immediately, with I've played hour long games.