Yeah I'm not sure this story makes sense either. Shoes may act as an insulator but wedding rings and belt buckles would presumably conduct.
Additionally potential differences tend to attract rather than repel unless these individuals were also charged with the same polarity as the field as far as I know.
When someone is talking about insulating shoes their point is that the body is electrically isolated from the floor. Without that isolation charge can travel between the two. Concrete and skin are fairly good conductors by comparison with air or insulators.
Wearing a conducting ring might make it easier for charge from the air to move into your body through your skin - but it will not make it easier for that charge to get to the floor (and then to ground) from your body.
Generally when people talk about shoes (or tires) they are talking about voltages that can jump the distance from their foot to the ground through air - around the shoe.
Most shoes are not great insulators - they insulate but how knows who much. electricians sometimes buy special shows that do insulate. Those shoes come with care instructions and dust on the outside compromises their insulation.
While you raise some valid points, you need 10kV to jump a 1cm gap. So in a domestic situation at the much lower voltage involved (130V / 250V) I imagine you don't need to worry so much about the air gap.
The care instructions and dust you mention sounds likely to be super important when you're casually touching live stuff while standing on a grounded floor.
In an electrostatic situation, the electrons can flow (almost) freely without the shoes / tyres and so a large differential between body / ground will not build up. With shoes, you'll need a large difference to build up (10kV? 20kV? More?) before it discharges.
Anyway, there is clearly a difference between these situations - even if the shoes don't provide magical protection. But the shoes are not magical, as you correctly describe.
The skin is very resistive, the body itself is not. There is a soldier who "won the darwin award" by taking the probes of a multi-meter and after measuring their skin resistance decided to measure their internal resistance.
After piercing the skin, the test current from the multimeter (9v) was sufficient to electrocute this person. Sadly it (apparently) was a fatal injury. I couldn't find a reference, but the logic makes sense (50V sufficient to kill normally, skin is most of the protection).
When dealing with electricity, having items which reduce the protection your skin offers (metal rings, moisturizer, etc) is a substantial risk.
Well, more correctly the difference needs to exceed the breakdown voltage of the insulation barrier. Or (depending on the insulator) some current might flow the entire time, but a limited amount.
