big brakes, why not the 2012 Stang GT

Nearly any drum brake can lock the tire up. It is a common misconception that once the brake is strong enough to do that then you're done - it can't get any better.

At their most basic description brakes turn Kinetic Energy in to Heat. The better that they are at dumping the heat into the air, the better their stopping power. That is why discs out-stop drums. They don't necessarily have more braking torque. It is that they are much better at dumping the heat that they generate into the air.

Can think of rotor diameter as being directly related to braking torque, and rotor width as directly related to heat rejection ability.

Can not ignore vehicle dynamics when considering braking force, and that plays a big part in braking traction.

If the tires are locking up, then the driver isn't doing his/her job.