Wine allows you to emulate games and play them on Linux.
-opengl argument is optional but in some cases it provides extra efficiency to the emulation.
Wine has a lot of bugs and problems. Emulating a game with Wine will never be as good as inside Windows.
All of these are rather wrong. WINE does not emulate games on windows, neither it is really meant specifically for games nor Linux. What WINE does is implement an open source version of windows API and directX. It DOES not emulate games or apps, it makes the stuff run natively, although as the API is a wrapper over the host OS' API it will get a little slower sometimes.
The bug list is misleading as most of the bugs in there are not confirmed. In the case of wc3 really, the problem is bnet, for some reason I can play in bnet, but some people cannot, this is approachable and you must include instructions in this tutorial as to how to fix it (Hint: Pipedream already told you).
bugs.winehq.org is not WINE's official page, it is WINE's official bug tracker. You should have used winehq.org
download the 1.21 patch (for modding)
Since most recent war3err works perfectly in patch 1.23 in WINE (using PEdit) , there is no need to use patch 1.21 (I don't)