Saga of the Beastslayer of First Founding

By jim7, in Deathwatch Rules Questions

I was looking through the Saga of the Beastslayer last night and saw that one of the outlines for a 'Beast' included having a Toughness of 10 or higher. Considering that humans are running between Toughness 20 and Toughness 35, it seems they're setting the bar pretty low. Does anyone know of any clarification of this rule?