suspension dynamics

[mudwaa]

this may be obvious but on the Pedders Suspension site there is a pic of an LS focus with lowering given as 600mm centre of rim to guard. Now this means they have obviously lowered the rear far more than the front thus changing the total dynamics of the cars handling. If i want lowering totally for the purpose of handling than the sus. should be lowered equally front and rear eg: 35mm. ???? Or is there a reason the rear is factory higher such as an allowance for towing?