I have serious doubts about this. About the fact that you create a "medium" quality model in 2-3 hours (even just a model without unwrapping, textures, bones, and rigging). Unless it's a model of some simple sword. Or a quick sculpt over a ZBrush base mesh.
In ZBrush, people create a complete model of a humanoid character with a quality much higher than what's needed for Heroes 5. I do it slower, of course, but not that slowly. I was talking about the import process itself, not about working with animations, etc. In The Elder Scrolls, you can import a model in two clicks, but in Heroes, you have to go through so much trouble, as if you were moving mountains.