Can some PLEASE explain the logic behind Revells seeming madness behind the moulding of the tracks on their 1:72 Panzerhaubitze 2000.

Here’s how the kit and instructions supposedly work and I hope that it’s not just my over taxed brain failing to work:

Step 7 – Right track assembly:
Parts 61, 62, 63, 64 and 66 x 10 make a perfect fit around the right hand drive and road wheels – I’ve built it to prove it.

Step 8 - Left track assembly:
Parts 61, 62, 63, 65 and 66 x 10 should go all the way around (according to the instructions) the left handside (bear in mind it’s an exact mirror of the right). But part 65 is two links shorter than 64 and as a result it’s too short !

Why in the name of all things normal are the left hand side tracks shorter?

Because in most modern armor vehicles that have a torsion bar suspension, one side of track is shorter than the other. The torson bars for each road wheel arm go through the entire side of the hull. Because of this, the road wheel arms are staggered with one side forward of the corresponding side.