no one would ride a pack horse to war, that would be stupid. They would flee once the fighting starts, because they were not trained to deal with such intense amounts of violence. Warhorses needed to be trained, by professionals, regardless of the breed or quality.
furthermore, CRPG is CRPG, cheap horses were necessary in native because they needed an immediate way to counter archery. In CRPG, you need to deal with it based on your build and your team's capabilities. Expensive horses prevent the retarded elephant mashing of Pre-january patch. Were you here for Gaga?