A different type of arcing protection for pylons

 I've posted before about arcing horns on pylons: http://wigtonphysics.blogspot.com/2015/03/arcing-horns-in-manchester.html I saw this on the way to Bridlington

Not horns as such but almost circles - like the Iron Age torc ornaments. I was wondering how the change in design might affect it. I've drawn field lines in green on the right hand set and there will be parallel fields lines all the way round so there will be a uniform field all round insulator. That will allow arcing for problems on any side of the insulator.