On my Xtreme 22, it's section #3 that goes first because I always have to extend it partially, so it wears inside and out like section #2, but there's more leverage on that section.
On my Xtreme 25, it's section #2, as I seldom use the other sections. Section #1 an #3 only wear on one side, the outside and inside respectively.
The other sections are only likely to break first due to accidents.