You can't sort armors linearly like plain < regen, composite > regen and so on. Stars don't make sense except obvious things: every researched armor > plain, upgraded ML > ml and such.
Armors are harder to do than engines or weapons, mainly because they have more unique properties. Whatever the attributes are (weight, price off the top of my head) they would be taken directly from the scripts themselves, so they would surely be quantifiable.
