This is a really hard one to actually figure out. I think mostly because depending on the skill level of the driver it changes. At a lower level assuming a good setup it's all about the drivers as they wont be able to notice the small setup tweaks as much and driver error will lose them far more time than gained from chasing after the perfect setup.
The higher the level the more setup becomes critical as you start to chase the 10th's of seconds and mistakes are less common.
All imo of course
