The fewer non-prime components, the more impact the prime has on the average. So the actual number is probably higher, sometimes much higher, based on the other division components, so the + sign is added as a reminder.
So the highest ('prime') component of Piercing or Armor multiplied by 40% or 30% respectively so gives a quick estimate for the minimum stats assuming everything else is 0 and the division is at full strength in equipment. Piercing = 40% of highest Piercing + 60% of “average” Piercing of the div componentsĪrmor = 30% of highest Armor + 70% of “average” Armor of the div components (wiki) My HOI4 Tank TD Pen Table.txt - 1936 UK info ingame stats edition March 12 2017
For the usefulness of this info see separate post.