that's great, and yea the rubbing of leather against ground is a good static discharge on its own. As long as its tested against electrical hazard, dielectric strength etc to ensure wearer is not harmed from lightning strike. I think they test it in both dry and wet conditions and infuse up to several k V but lightning can go up to million volts and would go through the least resistant (most conductive path) hence why some grounding shoes tend to come with lightning disclaimers.