Karl watched carefully and Hawk rested in the Beast Space as the fights continued, with the huge professor giving each of the students a chance to try against him. Karl had been the only one who really stood a chance, as the rest had all been training only against their own styles or had specialized in grappling and submission techniques, which wouldn't work on Tank.
But you didn't get to pick and choose your targets in a fight. There was a threat, and you had to deal with it, so this sort of training would be incredibly valuable to them later. Karl knew that there were many species of giant humanoid monsters as well. Orcs, Trolls, Ogres, Owlbears and many more.
This sort of training would work on them as well, with only a little modification.