The objective with spring rates and anti-roll bars is to get the handling of the car as neutral as possible. Different combinations of spring rates and bars will create a different roll stiffness at each end of the car, consequently affecting the roll couple distribution of the car and creating either a push (understeer) or loose (oversteer) condition.
If the front lower control arms are inclined too much, then the front roll center goes below ground level, thus creating a longer lever arm from the center of gravity.
Still playing with spring rates and bars on my HP Wabbit, and learning more every day about suspension handling...a big mountain to climb....Regards, Ryan.