Step back from the situation and consider it en toto. It seems that due to some nice research from
@jrgoffin the springs are the same. Also, the shocks are different and the swaybars are different. Why? Has anyone considered weight or wheel size and its effect on both suspension tuning and stance?
For example, is there any sort of extra "ballistic" padding in the door panels that might effect weight? How about expected weight overall? We already know that many of the parts in the rear have been strengthened to save trooper's lives when drunken idiots plow into them from behind while they're making a stop. There may be other reasons why it "appears" they are lower. The ST and the PIU definitely share the same platform, but they are addressing very, very different markets.