my AF Fine Tune numbers

My AF Fine Tune numbers puzzle me. I am fairly confident of the numbers. I use SpyderLensCal for the initial setting, then confirm the number with actual photos. I use two D700 bodies. Here are my numbers for my three f/1.4 lenses.

D700 #1
35mm 1.4G +12
50mm 1.4G -2
85mm 1.4G +10

D700 #2
35mm 1.4G +12
50mm 1.4G -4
85mm 1.4G 0

What I don't understand is how can the 35mm adjustment be the same for both bodies and the 50 and especially the 85 be so different.