JK_Dave
Caught the Bug
In theory, but fronts are larger because they are the primary braking instrument in a vehicle. Rears only come on for higher intensity braking (i.e sudden stops, complete stops) and experience less frequent use and less intense resistance under normal circumstances. This would require your front brakes which typically engage to slow you down most of the time (i.e. speed adjustments, low intensity deceleration) to be much larger so in practice, they wear out much faster.
Yaaa know?
Isn't it possible there are different compounds used for your fronts vs. rears? That could explain differences as well.