You have to consider the fact that WoW and WC3 are played from different perspectives. In WoW you usually play from third person and you see stuff that is in front of your character. So aside from the ground texture you would see mountains, hills, the sea etc. in WC3 everything is seen from above. Changes in terrain height don‘t appear as drastic. Most of the variation must come from the texture snd doodads within a limited view, unless it‘s for a cinematic.