Pretty sure they used nDo for Heroes? nvidia plugin is Terribad with a capital T. Also I think more of the newer hero models are sculpted in zbrush to start.
Individual artists had their own workflows, but most of heroes, especially early on were done with hand painted normals. Had to do with the fact that most the artists were really good at painting textures. Also the engine at the time worked really well with the Nvidia plugin. Oh I know lol