How do get that skidpad numbers don't tell crap about a cars handling?
Skidpad numbers are lateral g's that are created by turning the car. The higher the number, the better the overall grip/handling of a car. Its like the teletremy data that race car drivers go over after a race. Things that factor in here are chassis rigidity, tires & suspension
Slalom shows speed, and directly represents chassis agility and the ability for a car to change directions while at speed without loosing control. Factors here are drivetrain layout/car width/suspension/power.
Two different tests, two different forms of grip. Both equally necessary.