a worn ball joint (with up and down play) also causes the car to sit lower - its in the same plane of the height of the car and the spring pushes the arm down, Its the same sort of difference the spring pads make - just a little more than the pads as the ball joint is at the edge of the arm.

My car had replaceable joints (yours does not) and replacing them cured the problematic low, choppy and drunk ride my car had.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)