I'm never quite sure whether I understand these things or not*
but surely the lever is from pedal to BB, the same regardless of fancy shaped cranks? So all it does is add material (and coolness and a corner to possibly fracture at, oh and of course £$)? Those cranks also look very long, but maybe that's just the photo.
*I wished I'd realised in the past, at school, that physics could be interesting and useful. I suppose I could always blame my teachers.