Downloaded WBC3 off GoG on a nostalgic whim, and so far it runs well enough to play (CXG Mac 10.0.1.) Notable exceptions are that:
-Any settings above 800x600 seems to produce errors, where large sections of the screen become black and unresponsive.
-Skirmish runs perfectly, but there are problems with the single player campaign
-Campaign missions run perfectly, but the videos that play before/after missions can cause a crash to desktop. I've tried to find a way to disable the videos, to no avail.