Hmmmmm......Another rear wheel not "centered" under the rear fender. So we can conclude T design engineers didn't care.
the reason is as the axle comes up it gets longer. that is what i think. charley
the curve of the fender looks bigger than it needs to be, probably to allow room in back for mud that has flung loose from the tire., although it does seem a wee bit too close in front. and yes it would go a little further back as it comes up.