Staggered in width? Or in height?
It's not always as simple as square vs staggered. Various items like sway bars, spring rates, shock settings, weight balance, tire pressures, driving habits, etc can all have a significant effect on understeer and oversteer.
There is also a whole list of reasons why a car would come from the manufacturer like that.
2001 Mustang GT - Crashed (Other person's fault) Stock.
2003 Mustang GT - Sold
Lowered, Flowmaster catbacks, CAI + Tune, 5% tint all around, American racing wheels.
2005 Mustang GT - Traded in
"Performance" spark plugs and ignition coils, 5% tint on back 3 - 20% on front two, 20 inch silver AMR wheels
2011 Mustang GT - BEAST
5% tint all around. 2014 GT premium wheels. Roush axleback