To those who can't do math; BC edition

-30% of 50 armor is -15 armor.

-30% of 60 armor is -18 armor.

It was reduced to 24% because -24% of 60 armor is 14.4 armor and cutting off 1% from each was the easiest way to make it within 1 point of the old value.

The armor shred reduction was just an adjustment so that the armor item changes weren't also a direct buff to cleaver.