I agree that it would be rather appealing if the Bull is a much bigger, more muscular man. It could be a more muscular woman too, of course. It'd be interesting to see a story that delves into this topic. For example, a story where the MC is maybe wealthy and accomplished, but also weak or unsatisfying in bed. And the muscular wife takes control of their lives, openly showing how she dominates him, while having a much bigger stud have sex with her. It definitely plays into the domination aspect that's often associated here with female muscle.