Noone runs that kind of camber on drift cars. You want near 0 camber on rear wheels. Only the front has excessive camber since you need the front to grip when drifting. I have a full angle kit on my 350z and it is designed to be run at atleast 3.5 degrees of negative camber. It literately cannot be aligned with less camber.
Grip racing cars have more even negative camber. When you corner, weight is on outside wheels. Have camber allows more grip.
Almost noone has a slammed drift car because you'll run into clearance issues with front wheels and you'll destroy your fenders right away. The correct way to fix it would probably to set the bumpstops correctly, but noone bothers with it. We just raise our cars.
Having coilovers is one of the biggest differences in car performance. Its very apparent which cars are running stock suspension at an event. They all have excessive body roll.