The danger from higher kinetic energy comes from the longer break distance and time to stop: given the same driver reaction time and distance to the pedestrian, a heavier vehicle will take longer to break to a stop and thus have a higher velocity when it collides with that pedestrian than a lighter vehicle.

This is not to deny the difference that a higher front makes, just pointing out that kinetic energy does in fact make a difference, though of course as you point out not because of any "higher energy transmission on collision" or such, but rather indirectly because the vehicle is more likely to collide at a higher speed because it takes longer to break.

I couldn't find info on this for explicitly for light trucks, but here's some for trucks.