Where the wear comes in is during the cycling of the suspension, up & down. When stock, the change in toe and camber is not drastic. The changes have a somewhat smooth slope to it (if you placed a graph of change over spindle travel) at first and as the farther you travel the greater the slope becomes. Now if you already start on the middle of the travel (measured as a height difference between centerlines of axis and axle), the change in the slope is drastic and gets worst.
I hope I give you some understanding. Drop brackets help in this department as the geometry between front suspension and axle components remain relatively the same.