Originally Posted by bluntpencil
Unless there was some weird and unspeakable experiments with women going on, and that's why they're all so different.
There wasn't. They're all different because the Emperor wanted them different. Dorn the Champion, Guilliman the Tactician, Horus the Statesman, Lorgar the Speaker, Magnus the Scholar, etc. The Emperor wanted them that way so that they all wouldn't follow the same tactics and become stale and that they would be able to bounce ideas off of each other.