Hello, after about 10 frustrating hours puzzling I got it working on my mac (OSX 10.8.5, bit old).
This is what I did:
(1) Install VMWare fusion. (I used v6.0.2 which is also a bit old).
(2) Install Windows 7 Home premium SP1 32bit. (Also tried WinXP, but this caused major graphic problems.)
(3) Install War2Combat.
(4) Adjust VMWare fusion settings: Settings, Display, turn off Accelerate 3d graphics. (See screenprint "VMWare fusion settings".)
(5) Adjust Windows 7 screen resolution settings: Screen resolution, Advanced settings, Display, set Number colors to High colors (16 bits). (See screenprint "Win7 screen resolution settings".) (Not sure anymore if this step was necessary.)
(6) Adjust War2 exe file settings: Warcraft II BNE.exe, Properties, Compatibility, Access level, select "Run this program as administrator". (See screenprint "War2 exe file settings".) (Also not sure anymore if this was necessary.)
(7) Use the Win7 Colorfix tool from War2DotRuSlashDownloads to start War2Combat with the following settings: Window class name: War2Class, Window caption name: Warcraft II. (See screenprint "Win7 Colorfix settings".)
I tested by playing a multiplayer game with only computer opponents on the War2.ru server and did not find any problems (for example no graphic problems). This also works fine with the Warcraft II Battlenet edition from an old dvd on the Battlenet server. Finally, I can confirm that it does not work to install from dvd directly to Mac ("Classic games not supported").
Hope this helps.