The Transits definitely engage the rear brakes before the front. The upside to that is, the front of the van will rarely dip on you when applying the brakes.Many modern vehicles actually engage the rear brakes a fraction of a second before the front brakes for better stability. Hence rear brakes wear more.
The OEM pads are also very soft. Aftermarket pads are much harder and will last longer. At least the rotors are thick enough to last through 2 or 3 sets of aftermarket pads.
There is also a TSB out on some of the Ford Transits concerning the "backwards" mounting problem of the caliper mounting brackets at the factory, with excessive brake wear being the result.
In addition, the stability control utilizes the rear brakes, so they're gonna wear faster.