When I set up a network for a group I do it with the average or belowuser in mind, that way everyone else should be fine. The same thing when I teach a group of people find the least knowledgeable and the rest will be fine. I think they do the same thing with speed limits post them for the the average or bleow driver. Some people are just good drivers, have beter cars, took a course in rally driving
Call it what want to some good drivers drive slow, some bad drivers go fast vice versa.